Monday, October 19, 2009

At the intersection of evolution & intelligence   posted by Razib @ 10/19/2009 09:29:00 AM

If you're at ASHG, a session you might want to attend, Scale Effects and Recent Brain Evolution: Theory and Preliminary Evidence. Here's the abstract:
What forces have driven human evolution since the grand human diaspora? In this paper, I argue that the scale effects so central to endogenous growth theory in the field of economics (e.g., Kremer's widely-cited "Population Growth and Technological Change: 1,000,000 B.C. to 1990," Quarterly Journal of Economics, 1993) have been important drivers of human brain development since the diaspora. Scale effects have made prominent appearances in recent explanations of continent-level outcomes. For instance, in Kremer’s model, big continents create larger, denser, faster-growing populations. In Diamond’s Guns, Germs, and Steel model, wide continents raise the chance that an innovation will arise at a given latitude, an innovation which can then disperse across that latitude, enriching those who live on wider continents. In both models, the Malthusian nature of pre-Industrial Revolution existence imposes strong conditions on the general equilibrium outcome. My model takes those channels as given, and works out the theoretical implications for the divergent evolution of human brains on these continents. Brains are biologically costly, so evolution will only select for larger brains if there is a substantial payoff. And since larger brains tend to have higher levels of intelligence [corr(Brain Size, IQ)= 0.4 in recent in brain-scan studies], larger brains tend to have more processing and memory power. Under certain parameter values, Kremer’s and Diamond’s models both imply that the payoff to a big brain—a brain that can better adopt someone else’s ideas—will be higher on wider, larger continents. Thus, we would expect human populations living on larger, wider continents to develop larger, more powerful brains. I model this relationship formally. This result should only hold on average: intra-group diversity is central to evolutionary theory, and massive intra-group diversity is an important fact of quantitative human genetics. The main purpose of the paper is to set forth the model, but I include some tests of its implications. I discuss whether, as the model predicts, human brain size and average IQ correlate positively with continent size and continent width. Indeed, evidence generally supports this hypothesis. Further empirical testing of the model’s predictions will occur as future researchers employ genetic diversity databases. I plan to present the results in a manner intelligible to non-economists.

Here's the info:

Session Title: Evolutionary and Population Genetics Session

Session Location: Exhibit Hall II, Convention Center Session Time: Wed 9:30AM-3:30PM

Program Number: 643/W Poster Board Number:301 Presentation Time: Wed, Oct 21, 2009, 1:00PM-2:00PM

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Wednesday, October 14, 2009

Genes vs. environment, athletics   posted by Razib @ 10/14/2009 04:26:00 PM

The GSS variable GENENVO4:
Character, personality, and many types of behavior are influenced both by the genes people inherit from their parents and by what they learn and experience as they grow up. For each of the following descriptions, we would like you to indicate what percent of the person's behavior you believe is influenced by the genes they inherit, and what percent is influenced by their learning and experience and other aspects of their environment. The boxes on handcard D1 are arranged so that the first box on the LEFT (which is numbered 1) represents 100% genetic influence (and 0% environment). The next box (numbered 2) represents 95% genes (and 5% environment), and so on. The RIGHTMOST box (numbered 21) represents 100% environmental influence (and no genetic influence). After each description, please type the number of the box that comes closest to your answer. Please use the numbered scale on handcard D1 to indicate, FOR EACH OF THE BEHAVIORS DESCRIBED, what percent of the person's behavior you think is influenced by the genes they inherit, and what percent is influenced by their learning and experience. After each question, type the number of the box that comes closest to your answer. Remember, the higher the number, the more you think the behavior is influenced by learning and experience; the lower the number, the more you think it is influenced by genes 981. George is a Black man who's a good all-around athlete. He was on the high school varsity swim team and still works out five times a week. (Please type in a number from 1 to 21):

In other words, if someone gives the response 1, they think that George's athleticism is 100% a function of genes. 21, 100% a function of environment. The N for this variable is in excess of 2,000, and the question was asked in 2004. I decided to recode a bit so that responses were aggregated across 25% intervals like so: GENENVO4(r:1-6 "75% or more";7-11 "50% or more"; 12-16 "25% or more"; 17-21 "less than 25%"). If you want to poke around the GSS you can just cut & paste that into the "ROW" box. I was surprised at some of the results, first, the lack of difference across ages, as well as the similarity between liberals and conservatives. On the other hand, the dumb and uneducated were more likely to put an emphasis on genes, which went along with my expectations. The data are below in table form, and as well as a line graph (just to show you visually which ones deviate from the others).

% Genetic All Whites Black Male Liberal Conserv No College Degree College Degree Dumb Average Smart
75-100 21.1 19.3 29.6 21 21.7 19.6 24.2 13.8 28.2 23 15.1
50-75 27.8 28.7 28 26.4 29.4 24.6 26.5 31.1 31.9 26.8 27.6
25-50 22.4 23.4 16.2 23.1 24.8 24.5 20.5 27.1 11.2 22.4 25.6
0-25 28.6 28.6 26.2 29.4 24.1 31.3 28.9 28 28.7 27.8 31.7

At first when I saw little difference between liberals & conservatives and across age groups I wondered if it was coded wrong. But the outcomes for intelligence & education seem to fit. Perhaps it has something to do with George being a black athlete, so the intelligent and educated know what they should say about this sort of question?

Note: Dumb = WORDSUM 0-4, average WORDSUM 5-7 and smart WORDSUM 8-10.


Thursday, August 20, 2009

Differences in human universals on the margins   posted by Razib @ 8/20/2009 10:55:00 PM

Neuroskeptic reviews new research which reports that East Asians and Europeans perceive facial expressions differently. Yes, differences do seem to exist, at least within the small sample studied, but there is a great deal of overlap. Of course much of the phenomena of interest are on the margins anyhow. Speaking of which, Genetic and Molecular Basis of Individual Differences in Human Umami Taste Perception:
Population diversities of SNPs in TAS1R1 and TAS1R3 have been reported by Kim et al...Minor allele frequencies of the SNP at 372 in TAS1R1 vary among eight populations; 10% in Cameroonian, 0% in Amerindian (native Americans), 25% in North European, 35% in Japanese, 5% in Russian, 35% in Hungarian, 40% in Chinese and 6% in Pakistani, whereas those at 757 in TAS1R3 showed no obvious difference among populations. These results suggest that there may be differences in umami sensitivity related with TAS1R1-A372T among populations in the world.

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Tuesday, July 21, 2009

Genetic background & medicine, HIV & differences between blacks & whites   posted by Razib @ 7/21/2009 01:24:00 PM

The Duffy-null state is associated with a survival advantage in leukopenic HIV-infected persons of African ancestry:
Persons of African ancestry, on average, have lower white blood cell (WBC) counts than those of European descent (ethnic leukopenia), but whether this impacts negatively on HIV-1 disease course remains unknown. Here, in a large natural history cohort of HIV-infected subjects we show that although leukopenia...was associated with an accelerated HIV disease course, this effect was more prominent in leukopenic subjects of European than African ancestry. The African-specific -46C/C genotype of Duffy Antigen Receptor for Chemokines (DARC) confers the malaria-resisting, Duffy-null phenotype, and we found that the recently described association of this genotype with ethnic leukopenia extends to HIV-infected African Americans (AA). The association of Duffy-null status with HIV disease course differed according to WBC but not CD4+ T cell counts, such that leukopenic but not non-leukopenic HIV+ AAs with DARC -46C/C had a survival advantage compared with all Duffy-positive subjects. This survival advantage became increasingly pronounced in those with progressively lower WBC counts. These data highlight that the interaction between DARC genotype and the cellular milieu defined by WBC counts may influence HIV disease course, and this may provide a partial explanation of why ethnic leukopenia remains benign in HIV-infected African Americans, despite immunodeficiency.

Duffy status is a highly ancestrally informative trait. This is a case where the relatively low between population variance found among humans does not apply. Rather, it seems that the Duffy null phenotype is a recent adaptation to malaria among West Africans. Because malaria has such a strong fitness implication many independent genetic adaptations have emerged, many of them with other negative side effects. On net individuals with side effects may still have higher fitness in an environment where malaria is endemic. Sometimes the net benefit is most evidence on a population wide scale, sickle-cell anemia is a deleterious homozygote which exists because of the much higher frequency of heteryzogytes vis-a-vis wild type homozygotes. Many malaria adaptations exhibit the large effect dynamic and suboptimal characteristic which one might except from the early stages of natural selection in a Fisherian model. You deal with the adaptive pressures of the present and let the future take care of itself. In this case, the future involved HIV:
The researchers found that leukopenia was generally associated with a faster disease progression from HIV to AIDS, independent of known predictors of AIDS development. "On average, leukopenic European Americans progressed nearly three times faster than their non-leukopenic African or European counterparts," explained Hemant Kulkarni, MD, first author of this study. "However, leukopenic African Americans had a slower disease course than leukopenic European Americans, even though twice as many African Americans in the study had leukopenia."

The investigators found that the DARC variation, not race, explained the differences in WBC counts in African Americans with HIV. Among those who were leukopenic, only those with the DARC variation experienced a significant survival benefit. Additionally, this survival advantage became increasingly pronounced in those with progressively lower WBC counts, suggesting that the interaction between DARC and WBC counts was the primary influence on slowing HIV disease progression in African Americans.

There are no doubt details in the genetic architecture of those with the null genotype worth future investigation.

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Saturday, July 18, 2009

IQ & heart disease   posted by Razib @ 7/18/2009 10:21:00 PM

IQ Explains Some Of The Difference In Heart Disease Between People Of High And Low Socio-economic Status:
Authors of the study published in the European Heart Journal on 15 July...analysed data from a group of 4,289 former soldiers in the USA. They found that IQ explained more than 20% of the difference in mortality between people from socio-economically disadvantaged backgrounds compared to those from more advantaged backgrounds. Importantly, this was in addition to the classical, known risk factors for heart disease, such as smoking and obesity.
"The difference between the second and third analyses showed that IQ alone explained a further 23% of the differences in mortality between the higher and lower ends of the socio-economic spectrum, in addition to the other, known risk factors," said Dr Batty. “IQ wasn’t a magic bullet in this study, but this psychological variable had additional explanatory power on top of the classic variables such as smoking, high blood pressure, high blood glucose and obesity. It has partially explained the differences in death from heart disease and all causes."
...there could be three possible explanations for Dr Batty's findings: "(i) intelligence might lead to greater knowledge about how to pursue healthy behaviours; (ii) intelligence may "cause" socioeconomic position, i.e. more intelligence leads to more education, income, occupational prestige . . .; and (iii) intelligence may be a marker for something else, and it is that something else, early life exposures, for example, that leads to mortality."....

When correlations between socioeconomic status and health outcomes emerge, generally there is an assumption that the differences are due to disparate access to health care, or, more vaguely to the mysterious effect of low social status on someone's health. Matt Ridley actually posited the second explanation in Genome. As noted above intelligence does not explain everything, but its role is unfortunately not considered all too often. If, for example, intelligence has some correlation with time preference, and time preference modulates one's risk calculus, the causal chain which might result in disparate health outcomes is obvious. In The Myth of the Rational Voter Bryan Caplan has a reasonable number of references to the literature which show that the more intelligent may not be particularly rational in any absolute sense, but they are far more rational than the conventionally dull in a relative sense.

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Wednesday, May 27, 2009

Sex differences and variation in personality   posted by Razib @ 5/27/2009 05:21:00 PM

Look before you leap: Are women pre-disposed to be more risk averse than male adventurers?:
"It's not at all that women are risk averse," says Jody Radtke, program director for the Women's Wilderness Institute in Boulder, Colorado. When men are confronted with challenging situations, they typically produce adrenaline, which is what causes them to run around, hollering like frat boys at a kegger. An adrenaline rush is a good feeling, but when confronted with the same situation, women produce a different chemical, called acetylcholine.

"Pretty much what (acetylcholine) does is it makes you want to vomit," says Jody.

Because women don't have the same positive chemical reward, they tend to be less pumped about confronting stressful situations. This leads them to rely on decision-making. Essentially, they want the whole picture before they go diving in.

Research, Jody says, shows women have more cross-networking between the two hemispheres of the brain, which subconsciously allows them to evaluate different sensory cues, facts and emotions when making decisions. The cause of this difference probably lies somewhere in the debate of nature versus nurture and the history of evolution.

Marvin Zuckerman, professor emeritus at the University of Delaware, has studied risk for decades. He found men are typically more likely to take risks when seeking novel or exciting sensations, and that comes from both genetics and environment.

"What's important seems to be the environment that isn't shared by siblings in the same family," he says.

The above was originally published by Women's Adventure Magazine. The last reference is to the repeated finding that non-shared environment matters a great deal but isn't well accounted for. Obviously both men and women vary in terms of psychological attributes, and there have been plenty of attempts to adduce the variation to different quantities of neurochemicals (the "chemical soup" model is easy to translate into prose).

The content of the piece isn't too surprising, you see it all the time. Suggesting innate differences between men and women is totally acceptable so long as it is perceived to be neutral, or, better yet, casts women in a positive light. Michael Lewis' recent article on the Icelandic financial turmoil hints to sex differences and male psychology as a root problem. He presented a rather conventional stereotype of men as financial cowboys willing to take outsized risks for reward, while women were risk averse socialists. During the run up to the Iraq War and afterward I recall many people, mostly but not always women, calling into Leftish radio shows promoting a sex determinist theory that war was the result of the male nature, and the fact that men are head of states of most nations was the ultimate problem (this argument crops up in science fiction as well).

The interesting point to me is the sort of articles which highlight "different ways of thinking" between the sexes and how they might be rooted in biological differences have implications which point in different directions in terms of positive or negative valuation depending on your perspective and circumstance. As a specific example, the risk taking predispositions of many males can be seen to be folly and lack of prudence, but, risk often entails both an upside and a downside. Decisions which may seem foolish and wrongheaded viewed through a conventional mainstream lens are often lauded in hindsight as visionary. Unfortunately the nature of uncertainty is such that one has little idea which risks will pay off and which will simply extract a downside cost. It is likely that human societies dominated by those who are only risk averse, or those who are only risk accepting, would not be those which we would truly wish to live in. Variation in human personalities is probably beneficial in an aggregate sense when it comes to human progress. There are downsides risks to both the risk averse and risk accepting strategy, so it is probably best to have some of both. In an economic scenario what I'm talking about is straightforward; consider two individuals with degrees in computer science, one who goes to work for IBM and another who founds a start-up. You wouldn't want everyone to aspire to become a corporate employee, where would the innovation which drives productivity growth come from? On the other hand, there are only so many start-ups which succeed and there is a need for individuals who work in less sexy sectors who service older established technologies which are at the heart of the current economy. In other words, you want to be able to squeeze more juice from the oranges you have, as well be funding research which might result in the discovery of jucier varietals.

Addendum: Obviously what I'm saying here isn't too novel. It's rooted in human nature itself: our minds are cobbled together from disparate competencies and subfunctions, and our unitary consciousness is a delusion very successfully promoted by the prefrontal cortex. But even when it comes to concepts and assumptions which are the purview of the prefontal cortex its priority isn't usually to keep its story straight. Rather it seem geared toward generative ad hoc narratives which are only proximately consistent. Yes it can engage in rationality, but most of the time its forte is rationalization. And why not? Rationalizing the contradictory feels good! It was almost certainly highly adaptive in the past, and likely is today, in terms of keeping everyone in the group on the same page.

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Wednesday, January 14, 2009

Look me in the eye!   posted by Razib @ 1/14/2009 07:29:00 PM

Serotonin Transporter Genotype Modulates Social Reward and Punishment in Rhesus Macaques (paper is OA, so click through for stats & charts):
Serotonin signaling influences social behavior in both human and nonhuman primates. In humans, variation upstream of the promoter region of the serotonin transporter gene (5-HTTLPR) has recently been shown to influence both behavioral measures of social anxiety and amygdala response to social threats. Here we show that length polymorphisms in 5-HTTLPR predict social reward and punishment in rhesus macaques, a species in which 5-HTTLPR variation is analogous to that of humans.

In contrast to monkeys with two copies of the long allele (L/L), monkeys with one copy of the short allele of this gene (S/L) spent less time gazing at face than non-face images, less time looking in the eye region of faces, and had larger pupil diameters when gazing at photos of a high versus low status male macaques. Moreover, in a novel primed gambling task, presentation of photos of high status male macaques promoted risk-aversion in S/L monkeys but promoted risk-seeking in L/L monkeys. Finally, as measured by a "pay-per-view" task, S/L monkeys required juice payment to view photos of high status males, whereas L/L monkeys sacrificed fluid to see the same photos.

ScienceDaily has an interesting tidbit:
In a series of experiments, the S version of the gene in monkeys was found to influence their risk-taking when faced with particular social stimuli.

"Based on work in humans, we interpreted this to reflect an induction of a fearful emotional state, which often leads people to become risk averse," said Karli Watson, Ph.D., of the Duke Department of Neurobiology, lead author on the paper.

In human populations of European ancestry, 48% are S/L and 36% are L/L. The rest are S/S. The S allele is more common in Asian populations, Watson noted.

More on 5-HTTLPR.


Friday, January 02, 2009

Ethnic differences in morality   posted by Razib @ 1/02/2009 07:44:00 AM

Everyone & their mother is emailing me about Jonathan Haidt's new commentary in Edge, FASTER EVOLUTION MEANS MORE ETHNIC DIFFERENCES:
I believe that the "Bell Curve" wars of the 1990s, over race differences in intelligence, will seem genteel and short-lived compared to the coming arguments over ethnic differences in moralized traits. I predict that this "war" will break out between 2012 and 2017.

There are reasons to hope that we'll ultimately reach a consensus that does not aid and abet racism. I expect that dozens or hundreds of ethnic differences will be found, so that any group - like any person - can be said to have many strengths and a few weaknesses, all of which are context-dependent. Furthermore, these cross-group differences are likely to be small when compared to the enormous variation within ethnic groups and the enormous and obvious effects of cultural learning. But whatever consensus we ultimately reach, the ways in which we now think about genes, groups, evolution and ethnicity will be radically changed by the unstoppable progress of the human genome project.

Yes, psychopathy might have adaptive "strengths" in a frequency dependent context, but I don't think that's what Haidt meant! One difference with the IQ wars when it comes to personality is that it seems every single dopamine receptor has already been implicated in behavior genetic variation, while we're still a long way from IQ loci results which have been reproduced, though one might double-check on the details of the statistical analyses on suggestive findings from behavior genetics. In any case, since the heritability of behavior in economic games has already been established, it would be interesting if GWAs found some loci which tracked the variation. My own hunch is that personality variation is less continuous than IQ (characterized by a few morphs hanging around fitness peaks), with an underlying architecture of larger effect QTLs. Perhaps altruism is just way simpler to modulate than general intelligence?


Wednesday, December 24, 2008

Sex differences in math?   posted by Razib @ 12/24/2008 11:12:00 AM



Tuesday, December 16, 2008

What is that mystery parameter?   posted by Razib @ 12/16/2008 11:38:00 PM

Post-Columbian population movements and the roots of world inequality:
Why should we care about the apparently powerful influence that population origins exert on country and sub-national incomes levels?

First, if this influence is indeed as significant as our findings suggest it to be, then efforts to sort out the roles that geographic, institutional, and other factors play in explaining income levels and growth rates may produce misleading results unless we properly control for it.

Second, the influence of population origins suggests that there is something that human families and communities transmit from generation to generation -- perhaps a form of economic culture, a set of attitudes or beliefs, or informally transmitted capabilities -- that is of at least similar importance to economic success as are more widely recognized factors like quantities of physical capital and even human capital in the narrower sense of formal schooling. If we understand which culturally transmitted factors are important and what contributes to their emergence and propagation, we might be able to design policy interventions that could help less successful groups and countries to close their developmental gaps.

Also, Ancestors and incomes: More on the roots of world inequality. I don't doubt all sorts of implicit cultural norms, information, etc., are transmitted from generation to generation. But there's also something else which is passed from generation to generation which might come to mind....

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Saturday, December 13, 2008

NLSY blogging: Eye and hair color of Americans   posted by Jason Malloy @ 12/13/2008 09:28:00 PM

So sayeth Aggro in the thread down below:

"They should have measured eye and hair color -- we don't have any representative data! Seriously, they'll take extra long to measure all kinds of weird things that only an anthropometer would know of, but not eye and hair color."

I too have previously lamented this odd failure in easy measurement. A literature search had me coming up short for an adequate published sample of American eye and hair color. The best estimate I could cobble together from several small studies was that about 25% of American whites were blond. But, Ho Ho!, the National Longitudinal Survey of Youth is online and carries these simple treasures within its bosom.

The following hair and eye color information was self-reported in 1985 by a representative sample of those born between 1957-1965 (ages 20-28; currently 43-51). I've included blacks and Hispanics for the gender breakdown:

The first observation is that blond hair is exhibited by a little less than 20% of the white population; smaller than the estimates mentioned above. Second, consistent with Razib's previous look at published data from Iceland and the Netherlands, blue eyes are more common in men than in women. Also like the European data, green eyes are more common in women, though the NLSY difference is not as extreme. Blond hair is also more common in females. The trend in all three groups is for females to report lighter hair pigmentation; 66% of white males report darker hair, compared with 55% of females, and both black and Hispanic females are much more likely than men to report 'brown' hair instead of 'black'. Unfortunately, since the data are self-reported it's difficult to know how much of this is subjective. Is this a further example of lighter pigmentation in women, or does sexual dimorphism in pigmentation lead men and/or women to view their own pigmentation as more "sex-typical"?

I was also curious about how these figures differ for various European-American ancestries:

English ancestry Americans and German Americans are very similar for eye and hair color. Hair color is somewhat darker with the French and Irish, and much darker for Italians. Eye color is not darker for the Irish, but is again somewhat darker for the French, and much darker for the Italians.

Finally, we've also discussed the link between personality, behavior, and light pigmentation before, so I took some quick, rough looks to see if there was any signal within the English/German sample. The answer is: not from what I could see. There were no meaningful differences between dark and light haired people in getting in trouble with the police, in getting into physical fights at school or work, or in pregnancy before marriage.

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Friday, December 12, 2008

Height, weight, waist & BMI of Americans   posted by Razib @ 12/12/2008 09:59:00 PM

Steve has a modestly titled post up, Height and Weight, where he analyzes data from Anthropometric Reference Data for Children and Adults: 2003-2005 (PDF). This is government data on American men, women and children who are Non-Hispanic White, Non-Hispanic Black and Mexican American. I invite readers to peruse the raw data themselves. Steve did a little comparison of various parameters for males and females of the three populations. I thought it would be illustrative to plot the distributions of some the metrics so as to illustrate more intuitively the variation within the populations (the X axis are percentiles). Half Sigma pointed to Steve's post, and the discussion is unsurprisingly vibrant. I think it's safe to assume there is "structure" in something like weight within these populations due to geography and SES. You can see this even in New York City, just start from Bergdorf Goodman (especially around the Holidays) and walk north and east into the Upper East Side. Mean BMI starts dropping. In any case, like Steve I thought focusing on the 20-39 demographic was convenient, in part due to the nature of the readership of this weblog. Here's the CDC's BMI Calculator.

The data I used is here.

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Saturday, December 06, 2008

Human variation proportional to distance from Africa?   posted by Razib @ 12/06/2008 02:34:00 AM

Distance from Africa, not climate, explains within-population phenotypic diversity in humans:
The relative importance of ancient demography and climate in determining worldwide patterns of human within-population phenotypic diversity is still open to debate. Several morphometric traits have been argued to be under selection by climatic factors, but it is unclear whether climate affects the global decline in morphological diversity with increasing geographical distance from sub-Saharan Africa. Using a large database of male and female skull measurements, we apply an explicit framework to quantify the relative role of climate and distance from Africa. We show that distance from sub-Saharan Africa is the sole determinant of human within-population phenotypic diversity, while climate plays no role. By selecting the most informative set of traits, it was possible to explain over half of the worldwide variation in phenotypic diversity. These results mirror those previously obtained for genetic markers and show that 'bones and molecules' are in perfect agreement for humans.

The use of skull-traits is a little 1930s...but a trait is a trait. For you anatomy nerds (of which, I am not one), the list of traits is below the fold. And no, cephalic index is not on the list....
1. Maximum cranial length (GOL)
2. Nasion-opisthocranion (NOL)
3. Cranial base length (BNL)
4. Maximum cranial breadth (XCB)
5. Minimum frontal breadth (M9)
6. Maximum frontal breadth (XFB)
7. Biauricular breadth (M11)
8. Biauricular breadth (AUB)
9. Biasterionic breadth (ASB)
10. Basion –bregma height (BBH)
11. Sagittal frontal arc (M26)
12. Sagittal parietal arc (M27)
13. Sagittal occipital arc (M28)
14. Nasion-bregma chord (FRC)
15. Bregma-lambda chord (PAC)
16. Lambda-opisthion chord (OCC)
17. Basion prosthion length (BPL)
18. Breadth between Frontomalare temporale (M43)
19. Bizygomatic breadth (ZYB)
20. Middle facial breadth (M46)
21. Nasion prosthion height (NPH)
22. Interorbital breadth (DKB)
23. Orbital breadth (M51)
24. Orbital breadth (M51a)
25. Orbital height (OBH)
26. Nasal breadth (NLB)
27. Nasal height (NLH)
28. Nasal height (M55)
29. Palate breadth (MAB)
30. Mastoid height (MDH)
31. Mastoid width (MDB)
32. Breadth between Frontomalare orbitale - Frontal chord (M43(1))
33. Frontal subtense (No 43c)
34. Minimum horizontal breadth of the nasalia (sc) - Simotic chord (M57, WNB)
35. Simotic subtense (No 57a, SIS)
36. Breadth between zygomaxillare anterius - Zygomaxillary chord (M46b, ZMB)
37. Zygomaxillary subtense (No 46c, SSS)


Monday, November 17, 2008

Kenan Malik and Kerry Howely on race   posted by Razib @ 11/17/2008 05:29:00 PM

I really don't have much to add that's original, I've long tired of the "definition wars." Early this year Steve wrote a column rebutting some criticisms that Malik makes of his definition of race in Strange Fruit: Why Both Sides are Wrong in the Race Debate. The book is out in the United States now...I'm halfway through it, and there's nothing new to anyone who reads this weblog. The fundamental problem is that it is too easy to use the statistical inferences which are generated by human population genetics as a launching point for a thousand verbal shell games. Like the species concept debate I think pragmatists are well advised to be instrumentalists.

Here is what L. L. Cavalli-Sforza said 2 years ago after I asked him about Lewontin's Fallacy:
Edwards and Lewontin are both right. Lewontin said that the between populations fraction of variance is very small in humans, and this is true, as it should be on the basis of present knowledge from archeology and genetics alike, that the human species is very young. It has in fact been shown later that it is one of the smallest among mammals. Lewontin probably hoped, for political reasons, that it is TRIVIALLY small, and he has never shown to my knowledge any interest for evolutionary trees, at least of humans, so he did not care about their reconstruction. In essence, Edwards has objected that it is NOT trivially small, because it is enough for reconstructing the tree of human evolution, as we did, and he is obviously right.

In other words, between group differences may be both small and important. Whether this is so is an empirical matter.


Wednesday, July 09, 2008

Books of Interest   posted by birch barlow @ 7/09/2008 06:21:00 PM

Some sources/influences on my previous post, and my thinking in general, are listed below. I'm not recommending that everyone run off and buy all of these books, but they might pique your curiosity. Of course, to the extent one has time, it's always good to read and re-read the classic h-bd/evolutionary psychology writers such as Herrnstein & Murray, Sailer, Pinker, Dawkins, Dennet, and E.O. Wilson.

I consider all of these works, as those of Murray, Sailer, Pinker, Plomin et. al. to be good examples of what George Orwell called "the empirical habit of thought," which I believe is critical to understanding human diversity and defeating what Godless Capitalist termed the "Death Star 2.0" [see comments] version of PC. In fact, all the books below except (perhaps) for the textbook Multivariate Data Analysis make what are at least crypto pro-hbd statements. As an aside, one problem with crimethinking is that it tends to be decentralized and hard to find, much less to unite and make use of. Thus, I think it is useful to "think outside the box" in terms of finding pro h-bd works and thinkers.

Descartes' Error--Antonio Damasio

Spiritual Evolution--George Vaillant

The Wisdom of the Ego--George Vaillant

The Natural History of Alcoholism: Revisited--George Vaillant

What You Can Change and What you Can't--Martin E.P. Seligman

Multivariate Data Analysis--Hair et. al.

1984--George Orwell

Comment: O'Brien in 1984 spookily reminds me of Richard Lewontin and his disturbing capacity for doublethink and goodthinkfulness (i.e. willingness to swallow and propagate orthodoxy in the face of well-known facts, such as Lewontin's denying race and genetic influences on behavior in spite of his rather extensive knowledge of genetics and population genetics in particular). Lewontin strikes me as the kind of person who, if he were in power, would force people to be "re-educated" for speaking of the biological basis for human behavior, while unknown to the public, promoting the study of pharmacology, gene therapies, and genetic engineering as tools to increase his power and the power his pseudo-socialist State. In fact, the potential usefulness of biotechnology as a mind control tool is the one thing that makes me have some misgivings about it (though I am still very much in favor of the advancement of biotech).

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Have multiple intelligence theories really been disproven?   posted by birch barlow @ 7/09/2008 04:46:00 PM

[this is a slightly edited version of what was originally a haloscan comment]

I have come to believe that it is crucial to realize that there are other factors in intelligence besides g and its subfactors (e.g. math/performance, visuospatial, verbal, short-term memory). This is important not only factually and scientifically, but politically as well; a less g/traditional IQ-based theory of intelligence and human biodiversity is probably both more accurate and more politically palatable than a heavily g-centered one. The main drawback is that such a theory is also unfortunately quite complicated and difficult to test.

Many apparently non-g factors are almost certainly correlated with g, but they are not the same thing. In terms of higher-visibility phenomena, this would mean factors like creativity, motivation/drive, consistency, effective planning. In terms of lower-visibility phenomena, this would mean factors such as (neocortical) left brain/right brain ability, efficiency, and interconnectedness, as well as the interaction of such entities with the paleomammalian/limbic/midbrain and reptilian/lower brain/brain stem.

The main problem, in my opinion, is that these factors other than g are much harder to measure, and virtually impossible to measure on a 3-hour test, much less a brain scan (given current technology). Of course there are self-report tests for personality, creativity, motivation, and the like, but self-report tests are not, in general, terribly reliable. Also, insightful multivariate data analysis and effective experimental design for such analysis is hard to come by because these tasks are extremely difficult for even an intelligent person (in both the g and non-g sense) to carry out. Thus the failure of "multiple intelligence" theories in spite of the fact that it is clear that there are multiple intelligences.

If you are still unconvinced, how else would one explain a 25-year old with a 150 IQ, but also with Asperger's Syndrome/autism spectrum disorder, living on the streets while a 90-IQ illegal immigrant is living reasonably comfortably, and an intellectually uncurious and largely vacuous (outside of the classroom/lab/workplace) individual with only a 115 IQ is living large?(if you want a picture of the latter individual, think of Julia from (Orwell's) 1984 transplanted to the real America ca. 2008, or the devoted Asian [1] college student who seems to always be studying (high motivation/drive/tolerance for long, boring tasks) but has no intellectual interests and spends most of her/his [2] free time with sleazy entertainment, sleeping around, smoking pot, drinking, and popping pills [3]). Of course social factors such as biases against more autistic personalities may be partially at work, but most stereotypes and social biases have *some* basis in reality, even if they all too often facilitate cruelty and inefficiency. It is also important to remember that biological phenomena can lead to social phenomena (e.g. autistics, due to their biology, are repelled by (and repel) others, leading to a negative social reputation for autistics) just as environmental/social phenomena can lead to biological phenomena (e.g. autistics, due to their negative social reputation, increasingly have their biology wired for being hermits).

[1] and [2] Being intelligent but uncurious seems to be substantially more common amongst Asians (and perhaps amongst high-IQ blacks and Hispanics/Amerinds as well) than whites, and more common amongst females than males. This is only my personal observation, and it may be an entirely sociocultural phenomenon even if it is real.

[3] Nothing against sleeping around, smoking pot, drinking, or popping pills, but these don't tend to be the most intellectual activities in the world, in spite of common protestations to the contrary by horny drug users (such as, admittedly, myself) to the contrary. Also, I realize that immigrant (and particularly Asian) cultures are strongly biased against such hedonistic behaviors, but this bias tends to quickly fade amongst the children of immigrants, and even more so their grandchildren, as they become more modernized, Westernized, and Americanized.

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Wednesday, June 18, 2008

East Asian psychometric variance   posted by Razib @ 6/18/2008 11:42:00 AM

Asian-White IQ variance from PISA results:
The NE Asians performed about .5 SD better on average (consistent with IQ test results), and exhibited similar (slightly higher) variance.

Interestingly, the Finns performed quite well on the exam, posting a very high average, but their SD is slightly smaller. The usual arguments about a (slightly) "narrow bell curve" might apply to the Finns, but apparently not to the NE Asians.

Read the whole post to see if you follow the logic of the inferences; I've done some digging on this before to spot check the Europeans-higher-variance meme and didn't find much to support it, and some data to disprove it (though you could explain away that data because of clumping of distinct populations, etc.). That's the main reason I get irritable whenever this meme pops up in the comments, it's one of those "facts" which exhibits circular citation dynamics and spreads like wildfire. Of course, it isn't as if the meme is totally emerging out of a vacuum: if East Asians are so smart why aren't they as scientifically creative??? It seems to me that the most plausible explanation has to be that individual intelligence isn't sufficient for intellectual creativity, though it is likely a necessary precondition. Some of the other variables might be rooted in individual psychology (personality), but I suspect others manifest on a larger scale (e.g., the top-down paternalism and emphasis on conformity which is the norm in most East Asia societies).

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Monday, June 02, 2008

Selection speculation: CLOCK and reward-dependence in Africans   posted by agnostic @ 6/02/2008 02:39:00 AM

Since so many comments lead off with some variant of "I would guess," why not try to corrall them all into one post where they could serve a purpose? Each week I'll find some area of the human genome that shows signs of recent selection, see what phenotypes the gene affects, and although I'll likely provide the most convincing story, readers can conjecture to their heart's content about what might have driven selection. It may, for once, improve the discussion to comment while still deranged from last night's drink.

Let's start with the data: using Haplotter, we see that for the gene CLOCK, there is a signal of recent selection in Africans but not in Europeans or Asians. The CLOCK gene is involved in maintaining our circadian rhythm, and I started this search looking for between-group differences in being "day people" vs. "night people." However, other genes related to circadian rhythm -- PER1, PER2, PER3, Tim, CSNK1E, Cry1, and Cry2 -- show no signals of recent selection anywhere. So perhaps there is something else that CLOCK does that these others do not.

It turns out that CLOCK is also involved in the dopaminergic system, which regulates mood and behavior. None of the OMIM entries for the other circadian rhythm genes mentions dopamine, mood, the reward system, etc. So it is more likely that CLOCK has undergone selection for its effects on mood and on the brain's reward system, rather than on circadian rhythm per se. In mice, and so potentially in humans as well, mutations in CLOCK make individuals lower in anxiety and higher in risk-taking (Roybal et al. 2007; free full text).

Turning to data from Lynn & Martin (1995), which I turned into a convenient graph here, we see that Nigerians -- the African group that HapMap data come from -- are indeed the lowest in the world in the personality trait Neuroticism (the Israeli data-point must be a mis-coding by Lynn, who is known for doing so). They are also the highest in the world in Extraversion. Neuroticism measures a tendency toward anxiety and related states, while Extraversion measures, among other things, pace of living (manics living a faster-paced life) and excitement-seeking. So Nigerians show a psychological and behavioral phenotype that's fairly comparable to the mice with mutations in CLOCK, strengthening the hypothesis that selection at CLOCK has acted on personality rather than circadian rhythm per se.

Now comes the fun part -- telling a story about why this phenotype was more advantageous in Western Africa than in Central Europe or Northeast Asia over the past 10,000 or so years. The low-anxiety and high-excitement-seeking phenotype is suspiciously like that associated with derived alleles at the DRD4 locus, and the novelty-seeking 7R allele at that locus does show up at intermediate frequencies in Africans (Chen et al. 1999; see a map here). I concur with Harpending & Cochran (2002) (free full text), who argued in the DRD4 case that the phenotype is more advantageous in "cad societies" than in "dad societies."

More concretely, I suggest, based on the teachings of the pickup artist community, that low anxiety aids in approaching more females in a shorter time -- you are less paralyzed during the approach, and you get over rejection more easily -- and that higher risk-taking motivates you to approach more females. Contingent upon having other traits that are appealing to females (a muscular body, artistic skill, dancing or singing ability, a knack for flirting, and so on), the phenotype here would have increased male success in courtship of (multiple) females, a stronger determinant of reproductive success in a "cad society" than in a "dad society."

Lastly, here are two testable predictions: 1) lowland South American and highland New Guinean tribes should also show signs of selection at the CLOCK locus, since they are even more prototypically "cad societies," and they have the highest frequencies of the 7R allele at DRD4. And 2) African Bushmen should show no signs of selection at CLOCK since they are more "dad societies" and have lower frequencies of the 7R allele at DRD4. (ALFRED does not have data on CLOCK.)

The fact that Northeast Asians do not show signs of selection at CLOCK already supports the hypothesis, since they are more "dad societies" and have a very low frequency of 7R at DRD4 (and even the 2R allele, which shows up somewhat there, has a much more muted effect than does 7R). The lack of selection at CLOCK in Central Europeans is neither here nor there: they are more "dad societies" than Western Africa but not so much as East Asia; Europeans also have intermediate frequencies of 7R and DRD4. So we could have an example of "Rushton's Rule," where East Asians show no selection for low-anxiety / high-novelty-seeking alleles at either DRD4 or CLOCK, Europeans show selection at just one locus, and West Africans show selection at both.

To the best of my knowledge, as they say, this is the first argument for why Africans show a signal of selection at CLOCK. Consider it part of the graduate student with a PC trend in studying human evolution. You heard it here first.


Chen, C., M. Burton, E. Greenberger, & J. Dmitrieva (1999). Population migration and the variation of Dopamine D4 receptor (DRD4) allele frequencies around the globe. Evolution and Human Behavior, 20(5): 309-324.

Harpending, H. & G. Cochran (2002). In our genes. PNAS, 99(1): 10-12.

Lynn, R., & T. Martin (1995). National differences for thirty-seven nations in extraversion, neuroticism, psychoticism and economic, demographic and other correlates. Personality and Individual Differences, 19(3): 403-406.

Roybal, K., D. Theobold, A. Graham, J.A. DiNieri, S.J. Russo, V. Krishnan, S. Chakravarty, J. Peevey, N. Oehrlein, S. Birnbaum, M.H. Vitaterna, P. Orsulak, J.S. Takahashi, E.J. Nestler, W.A. Carlezon, Jr., & C.A. McClung (2007). Mania-like behavior induced by disruption of CLOCK. PNAS, 104(15): 6406-11.

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Tuesday, May 27, 2008

Group differences - within and between - pick a standard please!   posted by TangoMan @ 5/27/2008 01:59:00 PM

The debate over at The American Scene on Jim Manzi's article "Undetermined" is now closed to comments so I couldn't respond to one of the comments but the beauty of being a blogger is that you can use your own forum to vent your response.

The comment that I desperately wanted to respond to was left by Joe Shipman and reads as follows:
One thing that is established beyond any possibility of scientific doubt, of course, is that the genetic variability in IQ within races is much larger than the variability between races; any ethnic group of nontrivial size will have plenty of smart people and plenty of dumb people, and basing, say, educational policy on group rather than individual characteristics is therefore not only unAmerican but scientifically misguided.

Joe, will you join with me in advocating the complete dismantling of efforts to ameliorate the racial and gender wage gaps that exist, in that they too demonstrate that wage variability is larger within groups than between groups? I hit on this topic a few years ago:
It is important to recognize that most wage inequality occurs within and not between groups. The unweighted average Gini coefficient across all race, gender, and education groups was 0.256 in 1995, over 80 percent of the total Gini. Put another way, if all groups had identical mean wage rates (for example, black male dropouts had the same average wages as white male college graduates) but wages differed within groups as they do today, nearly all the inequality in wage rates would remain.

You know, if it's unAmerican and unscientific to craft social policy on observed group differences then surely the fact that the variability in Black or Hispanic incomes is greater within their groups than it is between their group and, say, Caucasians or Asians, is an unscientific and unAmerican basis upon which to craft social policy to address the between group differences in income. What's good for the goose is good for the gander, right Joe?


Tuesday, May 20, 2008

Gender & science   posted by Razib @ 5/20/2008 01:12:00 PM

My friend Jake Young has a post up, Contrasting Views on the Gender Disparity in Science:
Second, one of my primary arguments against innate differences in ability between men and women is that you are dealing with traits that have distributions and those distributions largely overlap. Making a statement about any individual man or woman is largely useless. The odds of a women or man selected at random being better or worse at math are not particularly different. This argument applies just as well to differences in preference. Maybe there are differences on average, but they are still distributions that overlap. The key question becomes: to what degree do those distributions overlap? How different on men's and women's preferences on average?

James Crow's Unequal by nature: a geneticist's perspective on human differences is apropos here:
There is actually a simple explanation that is well known to geneticists and statisticians, but not widely understood by the general public or, for that matter, by political leaders. Consider a quantitative trait that is distributed according to the normal, bell-shaped curve. IQ can serve as an example. About one person in 750 has an iq of 148 or higher. In a population with an average of about 108 rather than 100, hardly a noticeable difference, about 5 times as many will be in this high range. In a population averaging 8 points lower, there will be about 6 times fewer. A small difference of 8 points in the mean translates to severalfold differences in the extremes.


My conclusion, to repeat, is that whenever a society singles out individuals who are outstanding or unusual in any way, the statistical contrast between means and extremes comes to the fore. I think that recognizing this can eventually only help politicians and social policymakers.


Monday, April 07, 2008

Amy Harmon wins Pulitzer   posted by Razib @ 4/07/2008 04:34:00 PM

PULITZER WINNER: Harmon of 'NYT' Studied DNA After Birth of Child . Recall that Harmon interviewed a contributor to this weblog as well as Half Sigma for a recent article.

Via Jonathan Eisen.


Tuesday, April 01, 2008

Massive QTL for IQ discovered....   posted by Razib @ 4/01/2008 12:06:00 AM

Just got a note from someone I trust that a massive QTL for IQ has been discovered, on the order of 10 points in effect for a substitution of the the major allele for the minor (it's additive and independent, so homozygote minor allele ~ 20 points greater than homozygote major allele). The novel variant is found in an ethnic-religious minority population and no other phenotypic effects are discernble for those who carry the IQ boosting polymorphism. Everything is very preliminary at this point...but they've checked and re-checked and this seems to be real. There are two genes previous implicated in neurological pathologies in this region of the genome, so a molecular genetic & physiological story should be easy to extract.

I'm being a little vague on the details for obvious reasons; no one wants to be scooped. But word is spreading through the labs though, so my friend thought it might be good to prep the public and those at GNXP who are interested in this topic. Expect a Nick Wade article as soon as possible. Exciting times....

Update: Yes, April Fool's. Obviously I wasn't going to do something like taking down the site and pretending someone was going to sue us; you might recall that several GNXP readers sent the befuddled sysop of the Gene Expression Omnibus some irate emails....

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Monday, March 10, 2008

The de-brownification of brown people?   posted by Razib @ 3/10/2008 02:22:00 AM

About a year ago a paper came out, Low Levels of Genetic Divergence across Geographically and Linguistically Diverse Populations from India. The authors used Asian Indian groups from the United States, ergo, the caste/class representativeness is not is very typical. Additionally, there is a strong skew to Gujaratis since this group represents 1/2 of American Asian Indians. One could offer the reasonable opinion that the low amount of between population variance is simply a function of the fact that higher status groups across South Asia are not particularly differentiated from each other. I don't have a final opinion, but I would be moderately skeptical of this because I've seen enough work in the past suggesting that Brahmins, for example, are not particularly closely related to each across regions (and many of these regional Brahmin groups show strong evidence of gene flow with other local caste groups, though there usually there is some differentiation).

In any case, that's just a preface to the fact that a provisional paper has come out from the same group, Prevalence of common disease-associated variants in Asian Indians. If you're interested in the topic of the paper, all I have to say is that it seems that the major inference one might make is that more studies need to be done with Asian Indians because they likely have a whole lot of population-specific disease variants which aren't well known yet. Human biodiversity has some practical medical implications. But that's not what I want to focus on. In Table 4 they have some data on frequency of the minor frequency allele on SLC24A5, which in the case of South Asians is the ancestral variant. That is, the allele which is fixed in Africans and East Asians, and absent in Europeans, is the one shown in the table.

Language N Frequency of ancestral allele
Assamese 26 0.260
Bengali 27 0.293
Gujarati 181 0.208
Hindi 29 0.105
Kannada 24 0.268
Kashmiri 24 0.020
Konkani 43 0.058
Malayalam 25 0.259
Marathi 26 0.296
Marwari 25 0.041
Oriya 27 0.154
Parsi 25 0.100
Punjabi 28 0.052
Tamil 29 0.036
Telugu 28 0.000

There's nothing that surprising here. I wouldn't take some of the frequencies as scripture; I suspect that some of these linguistic groups are not representative (the frequency for the Gujaratis I can believe since I've seen it elsewhere, while the northwestern groups are in line with the ones from the HGDP populations). It seems likely that a strong NW-SE cline on the variation of this gene exists just as it does on many genes in South Asia. There is data which shows that in Sri Lanka the frequency of the ancestral allele is 0.75 for Tamils, and 0.50 for Sinhalese. I wouldn't read too much into these data either; but I've seen results elsewhere which would imply that you shouldn't be surprised at seeing a ancestral allele frequency around ~0.25 for South Asians on SLC24A5. I know this is a provisional paper, and this might get yanked, but I want to point this out:
The MAF [minor allele frequency] for the SLC24A5 g.13242G>A polymorphism [the ancestral allele] (0.114) in the Indian population is closer to that of Caucasian European populations (0.000-0.020) than to that of East Asians (0.979-0.989) and Africans (0.730-0.980)...This is surprising given that, as a whole, people of Indian origin have darker skin tone compared to Europeans. The East Asian and African populations share a similarly high frequency of the minor allele of the SLC24A5 g.13242G>A SNP, which in itself is surprising as East Asians are typically of much lighter skin than Africans. It is also interesting that the t-test suggested a greater similarity in MAF between Indians and those of populations in the Americas (Puerto Rican, Mexican, and Amerindian), who are of a similar skin tone....

No shit it's surprising. We know that SLC24A5 polymorphism can account for about 1/3 of the skin color variation in South Asians. It isn't as if it doesn't affect skin color in this population due to some modifier locus. The frequencies of SLC24A5 alleles in Latin American populations is just a proxy for European and non-European admixture; the non-European groups in Latin America are Amerindians and Africans, both of whom tend to carry the ancestral variant.

In any case, contrary to the impressions of those of you who only know of South Asians from Bollywood, Indians are on average darker-skinned than Puerto Ricans or Mestizos.
SLC24A5 has been under selection within the last 10,000 years. It explains 25-40% of the between group difference in complexion of Europeans and Africans (checked via an admixture study with African Americans). But there's no way I think that light skin was being selected in southern India within the last 10,000 years. Something else is going on....


Sunday, March 09, 2008

The shape of human variation   posted by Razib @ 3/09/2008 08:21:00 PM

Most of you probably know about the "species problem." The short of it is that even though the level of the species is probably the most justifiable one within the hierarchy of taxonomic systems (as opposed to say genus or order), it is not a cut & dried category. I tend to agree with evolgen that the nature of the species concept you use is going to be guided by instrumental concerns. If you are are focused upon taxonomy I have no doubt that the phylogenetic species concept is the bomb. On the other hand, if you are an evolutionary geneticist interested in speciation the details of the structure of the tree of life is less important. You would be more interested in how the branching occurs, in which case the biological species concept and its cousins are of more relevance. During the 18th and 19th century some taxonomists argued that their discipline had a claim to being the Queen of Sciences precisely because it was window into the mind and intentions of God's Creation. For these pre-evolutionary thinkers there was a religious and metaphysical significance in species; inappropriate classification would have distorted God's intent and obscured the grand beauty of his plan. Today we don't species aren't loaded with some metaphysical importance; our conception of the world does not hinge upon the battles between lumpers & splitters.

Which brings me to a lower taxonomical category; that of race. Or whatever you want to call it, you know what I mean! Obviously over the years on this weblog we've put the spotlight on specific issues such as Lewontin's Fallacy, which though seemingly abstruse can resolve confusions and misinformation being perpetuated in other domains. We've also pushed into more controversial territory like between group differences in behavioral tendencies & IQ, as well as less radioactive topics such as tissue matching problems across populations for transplantation. There's a lot of ground over the past 5+ years. But I believe there are 4 primary dimensions of variation, which though related (they aren't really orthogonal), get at different concerns.

1) First, there's the phylogenetic/total genome content angle. This is simply a form of Steve Sailer's race is an extended family argument. The tens of thousands of genes an individual has all exhibit their own distinct phylogenies; but they're not totally independent as a practical matter. We don't live in a perfectly panmictic world, population substructure is real. Just open up History and Geography of Human Genes; the classical autosomal markers exhibit correlations, which allow one to make assertions about population histories and relationships.

2) Second, there are the functional loci under selection. The story of lactase persistence in Europe & Asia is the best illustration of what I'm talking about here. From the North Sea to the Punjab a haplotype which likely arose around the Volga region has swept to high frequency within the last 10,000 years because of gene-culture coevolution. If you look at most other markers Middle Eastern populations will be closer to Europeans than peoples from the Punjab in northwest India (see the Fst values in History and Geography of Human Genes for example). But not on this locus. In fact, on this locus Danes are closer to Punjabis than they are to Sicilians, on average!1 Though most recently selected alleles will not break the cladograms you derive from neutral markers to ascertain phylogenetic relationships of populations, there will be plenty of peculiarities on the margins, and I have argued that these deviations are not trivial to our understanding of the history of the shape of human variation. Who can deny that the nature of genetic variation (or lack of) of indigenous New World groups was not of particular importance in relation to Old World people as a whole, as opposed to the undoubted phylogenetic reality that New World native peoples were a subset of East Asian Siberian populations.

3) This brings me to the dimension of salient phenotypic traits. No need for complex exposition of what I mean about this. Insofar as one looks at total genome content Melanesians are closer to the peoples of East Asia than they are to those of Africa. But if most people in the world were shown portraits of individuals from these three groups, and asked to generate an outgroup, I think most would assume that East Asians differed from the other two groups more than either did from each other. This is not to say that Melanesians and Africans look the same, or that Melanesians and Africans do not exhibit a great deal of within group variation in physical appearance, it is simply that the human brain strong affected by particular characteristics when generating classifications. Folk biology has a universal rationale, and is shaped by innate biases. Skin is our largest organ, and it is something that we as humans notice because there are strong adaptive reasons to scrutinize the skins of our conspecifics (fitness, disease, a rough & ready ascertainment of age). I agree with Steve Sailer that the monomanical focus on skin color which reigns in the American social discourse on race is a bit ridiculous, but I also think it is entirely expected and reasonable that skin color would loom large in any folk racial classification system. Many of the peoples which Europeans during the Age of Discovery encountered were referred to as "blacks." They were very different from each other, and Europeans recognized this. Today we know that all the non-African blacks are genetically closer to Europeans than they are to African blacks (who are characterized by a great deal of within group population substructure as well), but it is no surprise that a skin color terminology came to the fore. The West & Central Asian Muslims who ruled India during the medieval and early modern periods referred to themselves as white, and the natives as black. The Chinese would sometimes refer to the Khmer peoples as black as well, because that was a salient contrast. Of course other traits were recognized, and there is also a long tradition of Europeans suggesting that the peoples of South Asia were not truly black, but rather a very pigmented form of their own kind due to similarities of hair form and facial features. This sort of counter-argument was aided by the fact that a non-trivial proportion of South Asians even exhibit a brunette white complexion (usually along the northwest fringes).

4) This brings me to the last of the major ways in which we perceive human variation, and that is through the socially biased and constrained lens. Obviously this is affected by and contingent upon #3 to a great deal, but the boundary conditions are illustrative. In high school I was taking calculus with a friend whose mother was Scottish American and father was a Palestinian Arab. His name was an Arab one, but his physical appearance is by any definition "white." His skin is white, his hair is brown, his eyes hazel, and his features favored his Scottish as opposed to Levantine side (I had a 1/4 Lebanese friend who had a more recognizable Arab visage). Another friend, who was of vanilla Anglo origin as most of my classmates were, observed that we were the only two non-whites in the class, referring to myself and my aforementioned friend. Here's the irony: by any standard my Anglo friend was darker than my non-white friend, he had dark brown eyes, dark brown hair, and less of a pink pallor to his complexion. I recall kind of laughing at that assertion, and the teacher bitched me out about being disruptive and I laughed again. The point here is that the idea that taxonomical perceptions are colored by power hierarchies is not totally incorrect! In fact, it seems trivially obvious. I've been reading a fair amount on the Chinese & Japanese interaction with Western powers between 1500-1800. It is interesting that in the earlier commentaries on Asian peoples many Europeans observed that the Chinese and Japanese were white, unlike the peoples of South or Southeast Asia. After the last wave of Sinophilia receded after the mid-18th century there was a noted shift toward a perception of East Asians as being non-white. In other words, the whiteness of East Asian peoples (even if that whiteness was a different kind) inversely tracked the European sense of superiority to them.

I think #1 and #4 are pretty easy to understand. Thinking of race as an extended family simply co-opts our native intuitions about genealogical relations. In other words, it's an extension of preexistent software. As far as #4 goes, there's enough pointers from the current academic dispensation that we can comprehend the nuances. The main point is to map the dynamics more accurately upon reality and not elide the complexities inherent within socially constructed categories which are only partly informed by folk biology. A tendency to pretend as if whites and non-whites are the only two relevant categories prevents the acknowledgment of the realities of how various groups relate to each other (e.g., the social science data which suggests most American non-white groups prefer whites to other minorities).2 Since #3 is derived pretty directly from folk biology and some gross social cues it isn't too difficult. It's the practical definition of human variation which people in the United States have in their head.

#2 is a tricky one. I think it's really the most interesting one at this point, but I don't know how to really communicate it to people outside of a more technical framework. Alluding to selective sweeps and QTLs of large effect seems kind of important. #3 is actually a visible subset of this, and so I think when it comes to the general concept of how a functional locus may not reflect the evolutionary history of the whole genome that's a good place to start. LCT is also important, it's very well elucidated in all sorts of ways and so you can speak with confidence. Skin color is also a good case because people are generally aware of the trait and the general outline of inheritance patterns, and its putative adaptive significance. A lot of the work on recent human evolution is related to this dimension, so I think it's important for intelligent people to keep this angle in mind.

The main issue is not to conflate the various facets of human variation. There are ideological reasons that people will privilege one or the other, but in terms of utility that depends on where you stand. I'm obviously pretty interested in questions and issues where #2, to some extent #1 and #3, are very operationally the relevant background definitions. #4 is not something I deny, but it's not particularly interesting to me, nor does it speak to the questions I'm focused on. #4 has come to the fore with the ubiquity of international trade and travel, along with a host of social and political movements. That's all real, and it's all significant, but it isn't really normally part of my brief. It intersects with my interests only a specific case of psychological issues, or an indicator of social dynamics.

1 - By this I simply mean that if you draw a random Sicilian, Dane and Punjabi, and are asked to predict which group will be the outgroup when it comes to the most recent common ancestor on the locus LCT, it would be the Sicilian. On most of the other loci, it would be the Punjabi.

2 - I recall listening to a radio show about tensions between South Asians and people of black African origin. Several white callers were shocked and outraged, and asserted that such tension and racial antogonism between non-white groups was by definition ludicrous and incoherent. Both groups were non-white, ergo, they had common interests by definition. There's a little bit of the sense that some whites view non-whites as objects which only operate within the bounds of some deterministic framework, as opposed to conscious agents who act in response to specific conditions and their own perceived self-interest.


Thursday, February 28, 2008

Gene expression differences between populations   posted by Razib @ 2/28/2008 09:36:00 PM

Evaluation of Genetic Variation Contributing to Differences in Gene Expression between Populations (Open Access):
Gene expression is a complex quantitative trait partially regulated by genetic variation in DNA sequence. Population differences in gene expression could contribute to some of the observed differences in susceptibility to common diseases and response to drug treatments. We characterized gene expression in the full set of HapMap lymphoblastoid cell lines derived from individuals of European and African ancestry for 9156 transcript clusters...Gene expression was found to differ significantly between these samples for 383 transcript clusters. Biological processes including ribosome biogenesis and antimicrobial humoral response were found to be enriched in these differential genes, suggesting their possible roles in contributing to the population differences at a higher level than that of mRNA expression and in response to environmental information. Genome-wide association studies for local or distant genetic variants that correlate with the differentially expressed genes enabled identification of significant associations with one or more single-nucleotide polymorphisms (SNPs), consistent with the hypothesis that genetic factors and not simply population identity or other characteristics (age of cell lines, length of culture, etc.) contribute to differences in gene expression in these samples. Our results provide a comprehensive view of the genes differentially expressed between populations and the enriched biological processes involved in these genes. We also provide an evaluation of the contributions of genetic variation and nongenetic factors to the population differences in gene expression.

ScienceDaily has the digest.


Wednesday, February 27, 2008

More pathogens means more collectivism?   posted by Razib @ 2/27/2008 07:07:00 PM

Pathogen prevalence predicts human cross-cultural variability in individualism/collectivism (Open Access):
...We suggest that specific behavioural manifestations of collectivism (e.g. ethnocentrism, conformity) can inhibit the transmission of pathogens; and so we hypothesize that collectivism (compared with individualism) will more often characterize cultures in regions that have historically had higher prevalence of pathogens. Drawing on epidemiological data and the findings of worldwide cross-national surveys of individualism/collectivism, our results support this hypothesis: the regional prevalence of pathogens has a strong positive correlation with cultural indicators of collectivism and a strong negative correlation with individualism. The correlations remain significant even when controlling for potential confounding variables. These results help to explain the origin of a paradigmatic cross-cultural difference, and reveal previously undocumented consequences of pathogenic diseases on the variable nature of human societies.

The, r = -0.69 at p-value 0.001 and n = 68. You can find the raw data here. It would be cool to see trends within nations/societies. For example, variation in altitude.

Related: Toxoplasma gondii & human culture.

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Monday, February 18, 2008

Interracial marriage and Asian Americans   posted by Razib @ 2/18/2008 09:55:00 PM

As a follow up to Assman's last post I was thinking I should link to this article from Asian-Nation which parses Census 2000 data on interracial marriage of various Asian American groups. Do read the article (caveats appropriate to identity politics organs), but I just took their data and placed it below the fold. Also, I modified it a little and added the ratios of men to women who marry whites by generation and immigration status. That is, the Census broke up individuals according to whether they were immigrants, or US-raised or born. There are some caveats with analyzing the data in that way; Asian Indians and Vietnamese have only 1 US-raised or born generation which is actually marrying right now. These groups are post-1965, in contrast to Japanese Americans, who are predominantly US-raised or born, with many 3rd, 4th and 5th generation individuals. With that stated, I was surprised at the relatively moderate sex ratios when you constrain marriages only to those where both partners are non-immigrants; i.e., pretty much acculturated as Americans. Arguably the most assimilated Asian American group on this list, the Japanese, have the second most balanced sex ratio, 0.829 between males and females in outmarriage to whites. Why the most second balanced? Asian Indians are tops in terms of balance. In fact, when you look at all marriages men outmarry somewhat more than women in this group. But Asian Indians are a bit different than the others on the list in a whole lot of ways. Look at the very low marriage rates to "Other Asians" for example. These might even include Pakistanis, Bangladeshis, etc., overstating intermarriage with the other groups on the list. The full table below the fold....

Marriage Patterns for Six Largest Asian American Ethnic Groups (Oct. 2007), Source Asian-Nation

All spouses US born/raised X US born or foreign born US born/raised X US born/raised

Asian Indians

Men(All) Male : female outmarriage ratio - 1.28
(All US born) Male : female outmarriage - 0.862
Asian Indian91.973.356.7
Other Asian0.92.72.8
Multiracial & All Others0.41.62.7
Asian Indian93.677.554.2
Other Asian0.71.72.0
Multiracial & All Others0.50.91.9


Men(All) Male : female outmarriage ratio - 0.381
(All US born) Male : female outmarriage - 0.735
Other Asian4.511.511.6
Multiracial & All Others0.41.42.0
Other Asian2.77.37.8
Multiracial & All Others0.62.12.6


Men(All) Male : female outmarriage ratio - 0.338
(All US born) Male : female outmarriage - 0.779
Other Asian2.86.97.3
Multiracial & All Others2.36.38.4
Other Asian2.86.46.9
Multiracial & All Others2.54.05.7


Men(All) Male : female outmarriage ratio - 0.516
(All US born) Male : female outmarriage - 0.829
Other Asian9.912.49.4
Multiracial & All Others3.24.44.9
Other Asian6.48.07.7
Multiracial & All Others3.74.84.9


Men(All) Male : female outmarriage ratio - 0.232
(All US born) Male : female outmarriage - 0.663
Other Asian2.69.612.5
Multiracial & All Others0.41.72.7
Other Asian3.79.48.9
Multiracial & All Others1.11.82.3


Men(All) Male : female outmarriage ratio - 0.257
(All US born) Male : female outmarriage - 0.530
Other Asian2.97.05.8
Multiracial & All Others0.31.01.4
Other Asian3.58.27.8
Multiracial & All Others0.71.21.6


Thursday, January 31, 2008

Skin color is a deceptive character   posted by Razib @ 1/31/2008 01:05:00 AM

The figure to the left is from Signatures of Positive Selection in Genes Associated with Human Skin Pigmentation as Revealed from Analyses of Single Nucleotide Polymorphisms. I thought of this chart when considering the idea that the phenotypic races that we see around us might be relatively new; perhaps an artifact of recent human evolution. Look at "Oceania," those are Bougainville Islanders, from off the coast of Papua New Guinea. In the CEPH-HGDP populations the "South Asians" are from the much lighter skinned northwest fringe of the subcontinent; otherwise, I suspect you would be seeing the South Asian group moving toward the location of the Bougainville Islanders. This is not a surprising finding, earlier studies implied that very dark-skinned populations tended to exhibit a "consensus sequence" due to functional constraint; there's a reason humans are dark-skinned around the equator, and there's only one way to do it. But here's an important point: Bougainville Islanders are closer to East Eurasians than they are to other world populations in terms of ancestry. In other words, the dark-skin and the genes which confer that trait that results in an affinity between Melanesians and Africans in appearance is not a function of relatively recent common descent, but of local adaptation. Similarly, extreme dark-skinned South Asian groups are generally closer to Europeans in terms of ancestry than light-skinned East Asians.

This is all pretty common sense when you think about it. But with that said skin color is a very salient trait. The skin is our biggest organ, it's a large part of what others see. Therefore, there is a natural human tendency to classify in colors. If you read the reports from Chinese delegations who were sent to investigate Cambodia they describe the natives as "black." Similarly, according to Mary Lefkowitz the ancient Greeks observed that there were the blacks of Ethiopia and those of Southern India. They also noted that both the Egyptians and North Indians were brown-skinned people ("wheat colored"). But, perhaps importantly, they often distinguished the various peoples by other characteristics (e.g., Ethiopians and Indian hair form). So on the one hand you have an nod to the importance of skin color as a criterion of perception & categorization, and on the other hand an acknowledgment that populations differ in more than color. But in the United States there are peculiar social conditions which result in problematic conflations.

As everyone knows, to be very dark-skinned in the United States was identical to being of one race for a greater part of our history. Certainly there was a small Native American population, but they could be discarded from the shaping of social norms because of their low numbers. To have dark-skin was to be of African ancestry. Though there were certainly other distinguishing characteristics between those of African and European ancestry, skin color was the most visible and noticeable. It was used as the main discriminatory trait because that was all that necessary. This still persists in our folk culture when people talk about individuals "being discriminated against because of the color of their skin." Skin color connotes a racial identity. And yet you have groups like South Asians, who overlap with African Americans in complexion, but are not really"black" as we understand it. Steve Sailer has been noting for years the implicit value system highlighted by the reality that the very dark-skinned Vijay Singh is not identified as a black golfer, while the lighter-skinned (and only 1/4 African in ancestry) Tiger Woods is. Of course it doesn't work this way all the time, and South Asians are often identified as black, at least upon first impression. But the more confusing situations can also occur because of the nature of American categorizations. So tight is the correlation of non-white and "black" in the minds of some people that really peculiar characterizations can ensue. For example, in high school I had an acquaintance who would refer to myself & a Cambodian girl as black. That was understandable, we both had brown-skin. But, one day he referred to a Chinese friend of mine as black. This friend was not a dark-skinned, she had a brunette white complexion (not olive). When I queried my acquaintance about the fact that this "black" individual was probably lighter skinned than at least 1/3 of our other classmates (all of whom were white), he simply insisted that she was a "Chinese black." That was about as far as I got, obviously he couldn't express the inchoate associations within his mind between racial identity and skin color. In his world, there were whites and blacks. If someone wasn't white, that entailed that they were black.

As is rather clear from the content on this weblog we are getting a good fix on the genetics of pigmentation. Not only do we know the patterns of inheritance via classical pedigree analysis, but we now have a good grasp on which regions of the genome control world-wide variation in melanin content of the skin, eye and hair. We are even beginning to understand when selection began to occur on the loci which control this variation. We have some working hypotheses of why skin color is under functional constraint, and what sort of changes might drive adaptive evolution. But all this is sometimes harder to discuss because the typical American has so many social and psychological associations between skin color and group identity. It isn't just another trait, like bristles on the back of a Drosophila, no, it is the token of one of the most significant sociological phenomena which characterize American society today. Steve will have quite a bit to blog about into the foreseeable future.

Note: I suspect that the transposition of genomic knowledge to folk wisdom is easier in societies such as Brazil or India where extant phenotypic variation on this trait exhibits a larger range, much of it within families. Race and color are still very important issues, but the joints around which the perceptions are carved are more flexible and numerous.

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Sunday, January 27, 2008

What the shades of humanity should be   posted by Razib @ 1/27/2008 12:12:00 AM

From Geographic distribution of environmental factors influencing human skin coloration:
...The UVR [ultraviolet radiation] data recorded by satellite were combined with environmental variables and data on human skin reflectance in a geographic information system (GIS). These were then analyzed visually and statistically through exploratory data analysis, correlation analysis, principal components analysis, least-squares regression analysis, and nonlinear techniques. The main finding of this study was that the evolution of skin reflectance could be almost fully modeled as a linear effect of UVR in the autumn alone. This linear model needs only minor modification, by the introduction of terms for the maximum amount of UVR, and for summer precipitation and winter precipitation, to account for almost all the variation in skin reflectance.....

The map above was generated from the regression analysis. Apparently it has been updated as of 2007 (received the link from a friend). It does look much better than it did in the original paper (which I have read and have a PDF copy of). Do note that the selection of peoples whose reflectance values were plugged into the model obviously matters. But I still think it's interesting the sort of predictions this map produces and how it fits with our intuitions of what the distributions should be, and the knowledge of what they are. Note the equivalent latitudes in Europe and North America, or Australia.

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Friday, January 18, 2008

World turned upside down!   posted by Razib @ 1/18/2008 01:26:00 AM

A site with the URL puts up a post titled Fighting the mantra, "People vary more within the groups than vary between groups"? What's going on here! Since Lewontin's Fallacy is one of the axioms at the heart of much of modern anthropology (that is, when anthropologists bother to accept the validity of linear-logo-centric analytic frames), I think someone might have their card revoked soon. Be afraid! Of course, we know what type of person runs

Readers who want to dig deeper into the nature of the pretty charts in the papers that the apostate anthropologist mentions above should check out Inference of Population Structure Using Multilocus Genotype Data: Linked Loci and Correlated Allele Frequencies, an early paper introducing STRUCTURE. K's in the hiz houze, as they say.

Update: Some concern in the comments that I'm painting with too broad a brush in regards to anthropologists. Obviously since I am avid follower of the work of people such as John Hawks, Henry Harpending and Heather Norton, who are all trained as anthropologists, I don't think it's all crap. That being said, physical anthropologists are anthropologists in the same way that a follower of Milton Friedman is a liberals. There are historical and definitional reasons to call oneself a liberal in such a case, but quite often it simply results in confusion because of other definitions in circulation (context matters here, since the older definition of liberal is still in currency in much of the rest of the world). In this case, there is Anthropology which deals in Theory and Ways of Knowing, and anthropology which is driven by data, models and analysis.

Of course, this isn't a total dichotomy. There are cultural anthropologists who attempt to work within a scientific framework, general hypotheses, see how the data fits the inferences, and so forth. But they seem a very small minority at this point.


Saturday, January 12, 2008

Francis Crick & James Watson, peas in a pod   posted by Razib @ 1/12/2008 10:48:00 PM

Steve Sailer has the goods on Francis Crick via his private correspondence. To be short about it Crick seemed to be of the same general opinion as James Watson regarding issues such as race & intelligence; in fact, his survey of the literature & acquaintance with the principals was clearly more thorough. Is anyone particularly surprised by this? Many of the great British scientists were heterodox fellows who generally were disinclined to bend before the winds; note W. D. Hamilton's heresies. I believe that many of these individuals whose opinions and conjectures would raise eyebrows in polite company do approach controversial questions with the same objectivity as that when they study inheritance of bristle number in Drosophila (to paraphrase James F. Crow). I don't think it is any surprise that both W. D. Hamilton and Francis Crick mooted the positive aspects of infanticide. No common men, they. I suspect that their moral sense was a bit deviated from the central tendency...which isn't always a bad thing so long as you don't allow them to manipulate the levers of executive power in an autocracy.


Friday, January 11, 2008

East Asian & American brain activity - what does fMRI say?   posted by Razib @ 1/11/2008 05:20:00 PM

Culture Influences Brain Function, Study Shows:

To find out, a team led by John Gabrieli, a professor at the McGovern Institute for Brain Research at MIT, asked 10 East Asians recently arrived in the United States and 10 Americans to make quick perceptual judgments while in a functional magnetic resonance imaging (fMRI) scanner--a technology that maps blood flow changes in the brain that correspond to mental operations.

Subjects were shown a sequence of stimuli consisting of lines within squares and were asked to compare each stimulus with the previous one. In some trials, they judged whether the lines were the same length regardless of the surrounding squares (an absolute judgment of individual objects independent of context). In other trials, they decided whether the lines were in the same proportion to the squares, regardless of absolute size (a relative judgment of interdependent objects).

In previous behavioral studies of similar tasks, Americans were more accurate on absolute judgments, and East Asians on relative judgments. In the current study, the tasks were easy enough that there were no differences in performance between the two groups.

However, the two groups showed different patterns of brain activation when performing these tasks. Americans, when making relative judgments that are typically harder for them, activated brain regions involved in attention-demanding mental tasks. They showed much less activation of these regions when making the more culturally familiar absolute judgments. East Asians showed the opposite tendency, engaging the brain's attention system more for absolute judgments than for relative judgments.

As noted in the summary there have been previous behavioral/psychological studies which pointed to this difference, the book Geography of Thought surveyed that literature. I can't find the paper online yet, or on the site of Psychological Science, so the question I have is what was the ethnic make up of the "10 Americans"? In the previous psychological work it seems that Asian Americans tend to cluster with other Americans if they arrived as small children, but more with Asians if they arrived as adults (with teenagers somewhere in between). That argues for some level of plasticity in regards to this sort of cognition, or at least a critical period. If the fMRI confirmed this, that is, Asian Americans born in the United States exhibit signatures similar to European Americans, then that would suggest that this sort of cognitive function is subject primarily to cultural variation.

You might think "of course it is a function of culture," but do note that the physical differences in shape across brains. And recent signatures of selection show that East Asians have derived alleles on genes which are involved in development of the structure of the brain. Finally, East Asian and European infants seem to have very different initial personalities. So I don't think the priors here are clean cut at all. Culture influences the shape of our genome and biology; LCT anyone?

Note: If there is a difference between East Asians and Europeans even before or controlling for acculturation on these sorts of tasks, I would suspect that it would be a small average difference when considered in light of the difference phenotypes. I suspect that small differences in means can lead to different metastable cultural norms. Or, more clearly, small differences in propensity of East Asian origin people raised in Western culture to think in a particular manner may totally be dampened by the other exogenous inputs (primarily, the constant interaction with people of European origin with cultural norms at sharp variance with those dominant in East Asia). But as the frequency of East Asians increases one could imagine that a likelihood might exist that a "peak shift" might occur so that East Asian Americans in predominantly East Asian neighborhoods and socialized by those of the same ethnicity may develop a subculture more at variance with the European American norm and similar to what we see in East Asia. In other words, non-linearities due to gene-environment correlation & interaction.


Tuesday, November 20, 2007

Brown eyed girl?   posted by Razib @ 11/20/2007 02:27:00 PM

Peter Frost states:
I suspect there is some incipient sex-linkage, i.e., European women may be somewhat likelier to have non-brown eyes and non-black hair. If this sex-linkage is mediated by prenatal estrogenization there may also be some impact on personality and temperament. But I really don’t know, and unfortunately there are still more questions than answers.

I've read Peter's book, Fair Women, Dark men, and it is a great collection of data. Also, he has theorized that European color variation is a byproduct of selection selection. So I have been primed to look for a trend where women seem to express blondism or light eye color at higher frequencies. But I just haven't found anything like that. In fact, I've found data which goes in the other direction, that is, females have a higher frequency of brown eyes! But this really clinched it for me:

The source is this paper, Genetic determinants of hair, eye and skin pigmentation in Europeans. Note that women tend to score higher on skin sensitivity toward sun, which implies that they do have ligher skin. And as for hair color, well, perhaps there is a difference in how one judges blonde vs. brunette for males and females? I don't know. But the eye color data I've seen elsewhere and just dismissed it as small N or something like that. At this point my assumption is that there isn't really the sexual dimorphism in eye color that there is most definitely is in skin color. As for hair, I'm more open to this since it seems that it is subject to more genes, and there could be some hormonal factor as the tendency toward greater blondism in children and females is noted among Australian Aboriginals as well.

Anyway, forget visual inspection. Here's the associations taking sex into account (from Table 4 of supplementary info):

The authors don't want to make a judgment based on these data. But I'm not religious about 0.05 P values. And it looks like there's some action on KITLG anyhow.

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Monday, November 19, 2007

Blue eyed ice queens and brown eyed tarts?   posted by Razib @ 11/19/2007 01:10:00 AM

I'm interested in blue eyes. Specifically, I wonder why they're around at all. Unlike blonde hair, there's only one region of the world where blue eyes are extant at high frequencies, and there is a pretty regular drop off as a function of distance. It seems that variants of OCA2 are associated with blue eyes in Europeans. If you check Haplotter it looks like the region around this gene has been subject to a powerful bout of recent selection (i.e., within the last 10,000 years). Why this selection? Well, there's no definitive explanation yet. But I don't want to focus on hypotheses for why OCA2 has been subject to selection as much as what correlates there seem to be with the phenotype of blue eyes. Specifically, behavioral correlates.

There's a fair amount of recent work in this area, but reading Racial Adaptations I stumbled upon some older studies, and, a model to explain the outcomes which I'm not really qualified to judge. So I'm going to report and let you decide, and hopefully, inform (especially those of you with cognitive neuroscience backgrounds).

So here I go. From page 66:
...eyes of different colors are related to differents in perception and innate behavior, as psychologists have discovered.23 Some of their tests have shown that dark-eyed persons are more aware of color and lighter-eyed ones of form; the former prefer bright hues and the latter lighter ones. Light eyes tend to envision panoramas, dark ones to concentrate on details

I don't know anything about fashion or design, but I wonder if those of you who know this area (assman?) might be able to map some macrosocial trends back to these individual differences? After all, the vast majority of Scandinavians are blue eyed, and they've produced a fair amount of modern design. While Italians are well represented in the world of fashion and the arts. And the frequencies of eye colors are probably inverted in these two populations.

In any case, moving on, later on the page:
Behavioral variations are focused on the differences between "self-paced" and "reactive" responses to sudden stimuli. In the first subjects follow a well-known plan of animal behavior of pausing and deliberating before decision. In the second the subject flies into instant action (in animals), to attack or to flee. Of course, these behaviors are elaborated in man to govern many more-complex and subtler actions in speech and deed.

Light-eyed subjects are more likely to be self-paced, dark ones reactive. These differences are statistically significant and are patently genetic because they are equally represented in all age groups from kindergarten through professional life. When the iris color categories are extended from two to three, the subjects in the middle, with the mixed, green-to-hazel eyes, are found to share the benefits of the two extremes.

In one experiment ten of each of blue-eyed male, brown-eyed male, blue-eyed female, and brown-eyed female college students were wired to polygraphs and shown arousing pictures of sex and violence with appropriate sound effects. The brown-eyed subjects and the females responded more emotionally than the blue-eyed and male ones did.24

In another test, the same investigator gave Rorschach tests to forty blue-eyed and forty brown-eyed males. The blue-eyed ones fared better with form than with color and vice versa.25 In both tests only pure blue-eyed and pure brown-eyed persons were used.

That's a lot to throw at you, but pretty much line with more recent work. The author does note that these studies were performed upon subjects of European ancestry. Whatever differences one can see between groups of blue and brown eyed Europeans, obviously it wouldn't predict to other genetic backgrounds. East Asians tend to exhibit some of the same behavioral tendencies vis-a-vis Europeans that blue eyed Europeans exhibit vis-a-vis brown eyed ones. Obviously brown eyes can't explain this since East Asians have brown eyes. This isn't that strange, lots of the recent research in regards to human evolution suggests that East Asians and Europeans can converge upon the same phenotype via alternative genetic pathways. Blue eyes may simply be a byproduct of selection for another phenotype.

But on to the author's model, which requires some knowledge of cognitive neuroscience and brain chemistry to evaluate. From page 74:
Few people other than ophthalmologists seem to have looked at retinas, nor to have considered it remarkable that the fundus is of virtually the same color as the person's skin and for obvious reason that the underside of the retina is epidermis

At this point the author draws upon some photographs of the retinas of various racial groups, and observes the variation in color. He takes lithographs of these photos and basically measures the amount of light which can penetrate them. Here is the exposition that is relevant:
The Negro and the mulatto get 1.75 fcp; the Hindu and the American Indian 1.16 fcp; the brunet European 0.66 fcp; and the Chinese, the blond and the albino get 0.22 fcp. The Negro's and the mulatto's retinas let through eight times as much light as did those of the Chinese, the blond, and the albino.

OK, here's the part where he lays out his argument for color and behavior:
Once inside the cranial cavity, neural impulses produced by the visible light that has passed through the retinal screen follow one of two paths. One lot goes to the hypothalamus...This part of the brain is the primary control tower of the central nervous system for almost all of the self-starting and self-regulating activity of the body-the sleep cycle, body temperature, the digestive process, fighting and loving.

These activities are managed by the production inside the hypothalamus of regulatory hormones. In some cases directly, but more commonly indirectly, these hormones control the fabrication and release of other, more specialized hormones in the pituitary, or "master gland," seated in its bony saddle at the base of the braincase.

Two of these pituitary hormones become the raw material for making MSH (melanosome-stimulating hormone), so named because it darkens the pigment in amphibia and other cold-blooded animals. In man as in other mammals, it has yielded its pigment-darkening role to the built-in enzymes of the melanosomes themselves. Its only retention of its earlier function is to darken melanosomes.

Meanwhile, the rest of the neural impulses flow through a complicated channel into the brain's third ventricle. From there they continue through several different parts of the brain stem into the pineal gland.

...Among other hormones, the pineal makes melatonin, which flows onto the cortext...Melatonin is an inhibitor; MSH is a stimulator, and one of its results is the secretion of a substance that switches melatonin making in the pineal on and off in countermeasure with is own rate of flow. Thus, the more light the retina lets in, the more MSH will be secreted and the less melatonin.

MHS has two affects the peripheral nervous system only, the other may reach the brain, while melatonin bathes only the latter...all else equal, the stronger the light that penetrates the retina the more automatic are the responses to it, and the weaker the light the more the same responses fall under the control of the learning and thinking part of the brain....

To show those who may doubt that MSH and melatonin really affect the behavior of mammals...the National institute of Child Health and Human Development of Bethesda, Maryland, removed the pineal glands from some black rats (hair color, not skin color), pretended to do so with others, and left a third lot unscathed. The victims of real surgery became hyperactive and nervous, but when she injected melatonin into them they calmed down; both the other lots behaved normally throughout.29 Other researchers have given their animals shots of melatonin without operations. These injections reduced their avoidance responses,30 making them pause in the face of danger, rather than fight or flee. These are the "self-paced" and "reactive" responses found among blue-eyed and black-eyed students.

But not all our melatonin is made in the pineal gland. In daylight the choroid, which encases the retina, makes more of this hormone than the pineal does, and in darkness the pineal secretes more than the eye does. This discovery was made by experiments on chicks and rats.31 If one seeks to apply it to man, it might be well to remember that the stroma, or outer part of the iris lying above the lens, is mesoderm and an extension of the vascular choroid, also mesoderm, in contrast to the retina, which is ectoderm, like the pigmented layer of the skin. An investigation along this line might possibly explain the differences found in reactions blue blue- and brown-eyed subjects by psychologists mentioend earlier, because blood from the choroid flows direclty into the main bloodstream, some of which feeds the brain.

That was a lot to throw out there, but the main reason I'm posting this is so that cognitive neuroscience people can throw cold water on this model or not. Obviously a lot has happened in neuroscience since the 1970s, when the author thought this idea up. Myself, I tend to get confused on the various biochemicals which modulate brain chemistry and all the different pathways and modulations, so clarification would be nice too. Two points I'd also like to point out. 1) the Chinese clustered with the blond European in terms of the retina light values. 2) If the amount of light which manages to get through the retina is a major issue, that can explain variation by latitude and climate in terms of temper and personality, since obviously the amount of sunlight and radiation which reaches the surface varies a great deal.

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Pigmentation variation in Europe   posted by Razib @ 11/19/2007 12:59:00 AM

In the interests of putting informative physical anthropological data on the web, here is something I scanned out of Racial Adaptations. The map below the fold combines both hair & eye color data.

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Monday, November 12, 2007

Important New York Times Article   posted by Jason Malloy @ 11/12/2007 03:20:00 PM

In DNA Era, Worries About Revival of Prejudice by NYT genetics reporter Amy Harmon is a frank and sensitive look at the burgeoning implications of genetic science to our political and social landscape.

Nothing quite like this article has ever really appeared in the press. The underlying message is that the biological information environment is changing rapidly and if we don't start opening up the tightly monitored public forum for it right now, we are endangering our ability to handle its potential revelations with any sort of real preparedness or rationality. We, as a civilization, can't just keep silencing and punishing everyone who broaches these topics in a way that challenges our hopes and visions about human equality. The result is to shut down the discussion completely and disarm ourselves to ideas that are most likely - to some degree - correct.

I appear in this article. The quote is a tiny part of many emails and phonecalls I shared with the reporter in which I stressed that the political implications of genetic differences are still open. I urged that liberals and people of all ethnic groups stake out a territory right now, so the rug doesn't get pulled out from under them. I urged progressives to stop predicating their ideas of justice so religiously on empirical matters which might very well get falsified (leaving the door wide open for rival ideologies). When they do this, open talk or diverse public opinions about genetic differences will not evoke the same level of political threat. Ideally it would be irrelevant.

The time for taboos on this topic needs to end. It needs to end because these are issues we, as a diverse world and society, need to discuss and debate openly and fairly, in order to prepare for and accommodate our natural differences as human beings.

And for new readers coming in through the Times, my defense of James Watson mentioned by Harmon, James Watson Tells the Inconvenient Truth: Faces the Consequences, is here.

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Tuesday, November 06, 2007

Hair thickness, update   posted by Razib @ 11/06/2007 10:12:00 PM

This is an update on my previous post about hair thickness. In this post-genomic era the precision and data density we gain from more powerful techniques and sharper analytical techniques when it comes to genetic variation is not always supplemented by a concomitant increase in characterization of phenotypic variation. Sometimes it is best to look to older works from the lost age of physical anthropology; from page 63 of Racial Adaptations, the following data:

Area of the cross-section of hair in square millimeters
0.126 African
0.135 Blond European
0.193 Solomon Islander
0.204 Chinese

Weight in milligrams of a five-centimeter segment of an average hair
2.10 Brown haired European
2.15 Blond haired European
2.71 African
3.85 Black haired european
4.95 East Asian

Volume of five-centimeter segments of three kinds of hair two previous studies had in common
6.30 African
6.70 Blond haired European
10.2 East Asian

Weight-to-volume ratio
1:2.3 African
1:2.4 Blond haired European
1:1.2 East Asian


Wednesday, October 31, 2007

James Watson Tells the Inconvenient Truth: Faces the Consequences   posted by Jason Malloy @ 10/31/2007 11:22:00 AM

... [M]ight it be fair also to say that the champions of 'no difference' in race or sex, or intelligence ... are the guardians of a greater 'untruth' that allows people to live together in mutual harmony, implying that these critics really deserve to be praised as our protectors even when they are factually wrong? ... it is roughly how the self-appointed guardians choose to present themselves - leaving aside, usually, the step of frankly admitting that they are promoting factual untruths when they know that they are.
W.D. Hamilton - ("... one of the greatest evolutionary theorists of the 20th century"). Narrow Roads of Gene Land. Vol. II: The Evolution of Sex, p 332.

The public intellectual forum is being manipulated with intimidation and coercion and you are being lied to. The media is not doing its job, and the scientific community is not playing its proper public role as a beacon of dispassionate truth seeking, as a conduit of knowledge to the public, or in fostering an open and fair intellectual climate. Both are abusing their power and authority to do the opposite of their honor bound social and intellectual roles; facts are being distorted in service of values.

This post is a very long and detailed examination of what James Watson said, what the data reveal about James Watson's claims (i.e. are they, or are they not factually accurate), and what the media and scientists told the public about what the data reveal about James Watson's claims.


It's difficult to name many more important living figures in 20th century biology than James Watson. He ushered in the current age of molecular biology with his achievements in 1953, he built up one of the world's greatest biological research facilities from damn near scratch, and he is a former head of the Human Genome Project.

Given such an august curriculum vitae, you would think that this man perhaps understands just a few things about genetics. But given only the condescending media coverage, you'd think this eminent geneticist was somehow "out of his depth" on this one.

In his interview with the Times on Oct. 14th, we learned that:
... [Watson] is "inherently gloomy about the prospect of Africa" because "all our social policies are based on the fact that their intelligence is the same as ours - whereas all the testing says not really", and I know that this "hot potato" is going to be difficult to address.

These thoughts were a continuation of an important theme in his new book Avoid Boring People:
... there is no firm reason to anticipate that the intellectual capacities of peoples geographically separated in their evolution should prove to have evolved identically. Our wanting to reserve equal powers of reason as some universal heritage of humanity will not be enough to make it so.

Although Watson's book had already been out for a month with these more euphemistic, but still obvious, comments on race and intelligence, no one expressed any outrage. In fact the reviews were reverential and universally positive.

The explicit reference to intelligence and people of African heritage in his interview was clearly a violation of a much more formidable taboo. Still I am not aware of there being much noise about it until Oct. 17th when the Independent caused an immediate stir by calling attention to the remarks: Africans are less intelligent than Westerners says DNA pioneer.

There's no point in rehashing the rapid sequence of events in detail: several of Watson's sold-out speaking engagements were cancelled, many critical articles appeared in the British press, trailed by the American press a few days later, hundreds of blogs were fuming with negative commentary, including ones by the editors of Scientific American and Wired Magazine, a number of associations issued statements condemning his words, and soon he was suspended from his chancellorship at Cold Spring Harbor. Watson cancelled his already ruined book tour and flew home to tend to the destruction. It was too late; the eminent biologist retired in disgrace on Oct. 26th.

One thing, though, was conspicuously missing from this whole irritating denouement: any semblance of factual refutation. There is good reason for this: everything Watson got in trouble for saying was entirely correct!


The "scientific community" is a broad and inappropriately encompassing term, but to the extent such a thing exists as a social or public entity (I'm not talking about the research literature), it is fair to say it has pronounced Watson's claims not only false, but also outside the bounds of "legitimate" scientific discourse. Since only a small fraction of scientific disciplines have any relevance to Watson's claims, it is clear almost all of these scientists are just evaluating the claims with the same ignorant, moralized mental framework people in the general public use to look at (and editorialize upon) scientific claims about evolution.

Watson's claim was that intelligence testing shows lower intelligence scores in Africa than Europe. Is this or is this not true? The Science Museum in London responded by canceling Watson's speaking engagement by deeming this claim, not only scientifically false, but outside the realm of "legitimate" scientific inquiry (Whatever that is!) altogether:
In a statement, [The Science Museum in London] said: "We know that eminent scientists can sometimes say things that cause controversy and the Science Museum does not shy away from debating controversial topics.

"However, the Science Museum feels that Nobel Prize winner James Watson's recent comments have gone beyond the point of acceptable debate and we are as a result cancelling his talk at the museum."

Watson's claim was that intelligence testing shows lower intelligence scores in Africa than Europe. Is this or is this not true? Francis Collins, Watson's successor over the Human Genome Project, told the media this is not true:
Dr. Francis Collins, director of the National Human Genome Research Institute, said that "I am deeply saddened by the events of the last week, and understand and agree with Dr. Watson's undoubtedly painful decision to retire in the aftermath of a racist statement he made that was both profoundly offensive and utterly unsupported by scientific evidence.

Watson's claim was that intelligence testing shows lower intelligence scores in Africa than Europe. Is this or is this not true? Rick Kittles told the media this is not true:
Rick Kittles, an associate professor of genetic medicine at the University of Chicago, said Watson's remarks aren't backed by science.

Watson's claim was that intelligence testing shows lower intelligence scores in Africa than Europe. Is this or is this not true? Robert Sternberg told the media that the 'scientific findings' show otherwise:
Robert Sternberg, a prominent researcher on race and IQ at Tufts University, called Watson's statement "racist and most regrettable."

"It is unfortunate that some people with great expertise in one area sometimes lose their sense of perspective and come to view themselves as expert in areas about which they know nothing," Sternberg said Thursday in an e-mail response to questions. "They then proceed to embarrass themselves as well as society in general with their comments that express their own ideology rather than scientific findings."

Watson's claim was that intelligence testing shows lower intelligence scores in Africa than Europe. Is this or is this not true? Steven Rose told the media that the scientific literature shows otherwise:
Steven Rose, a professor of biological sciences at the Open University and a founder member of the Society for Social Responsibility in Science, said: "... If [Watson] knew the literature in the subject he would know he was out of his depth scientifically, quite apart from socially and politically."

Watson's claim was that intelligence testing shows lower intelligence scores in Africa than Europe. Is this or is this not true? The Federation of American Scientists issued a statement condemning Watson, claiming that there is no scientific literature showing this:
The Federation of American Scientists condemns the comments of Dr. James Watson that appeared in the Sunday Times Magazine on October 14th... The scientific enterprise is based on the promotion and proof of new ideas through evidence, however controversial, but Dr. Watson chose to use his unique stature to promote personal prejudices that are racist, vicious and unsupported by science.

Unfortunately our esteemed band of sputtering media scientists forgot to provide, in all of these instances, any of their allegedly voluminous citations to the contrary. Allow me, then, to take a different position, with the added benefit of evidence:

James Watson is one of the most important living figures in American science. The claim in his new book Avoid Boring People, that basic evolutionary logic predicts we should expect intelligence differences between racial groups is, if anything, an uncomplicated truth. Watson's claim in his recent interview with Charlotte Hunt-Grubbe that intelligence testing shows lower scores in Africa than Europe is likewise, entirely supported by the scientific literature. As is Dr. Watson's statement that there are many talented people of African descent, which clarifies he is speaking of different average scores, not that said populations are homogenous.

Below I am adding 65 psychometric intelligence study citations for sub-Saharan Africa, collected in IQ & Global Inequality, Race Differences in Intelligence, and IQ & the Wealth of Nations. The citations cover 47% of SS African countries or 78% of the people by national population numbers. The studies vary in quality, sample size, and representativeness, but broadly agree in their findings. Representative studies of the school age population with large sample sizes do not exhibit higher scores, much less scores that approach anything like European norms.


Sub-Saharan Africa
Countries: 43
W/ data: 20 (47% coun/78% pop)
Studies: 65
IQ: 68

West Africa
Countries: 20
W/ Data: 6 (30% coun/65% pop)
Studies: 15
IQ: 67

Central Africa
Countries: 5
W/ Data: 3 (60% coun/80% pop)
Studies: 9
IQ: 64

East Africa
Countries: 8
W/ Data: 5 (63% coun/93% pop)
Studies: 16
IQ: 72

Southern Africa
Countries: 10
W/ Data: 6 (60% coun/76% pop)
Studies: 25
IQ: 69


The recent August issue of the European Journal of Personality features a paper titled The g-factor of international cognitive ability comparisons: the homogeneity of results in PISA, TIMSS, PIRLS and IQ-tests across nations by German psychologist Heiner Rindermann. This paper includes an open peer commentary by 31 international scholars, as well as a response by Rindermann. The target paper provides valuable new IQ data from sub-Saharan African, or rather let's us know we have an overlooked source of intelligence data. I am adding these papers to the gnxpforum files section for you to access.

Starting in the 1960s and picking up pace in the early 1990s various well-implemented student assessment tests have been conducted for the purposes of international educational comparisons, including the Trends in International Mathematics and Science Study (TIMSS), the International Educational Achievement (IEA) measures, and the OECD's Programme for International Student Assessment (PISA). The cross-cultural test construction, sampling techniques, and quality control for these tests are exemplary. These international tests have also included half a dozen sub-Saharan African countries, and the test construction and sampling techniques are likewise very good. For example Ghana, Botswana, and South Africa were included in TIMSS 2003. For each tested grade level, at least 5000 random students from 150 schools were tested in these countries.

Gene Expression bloggers recognized the strong correlation between these types of tests and IQ as far back as 2004, but recently this has reached the academic literature. Last year Richard Lynn and Jaan Mikk reported correlations of .92-1.00 between IQ and TIMSS 2003 for math and science.

In his paper, Heiner Rindermann takes this sort of analysis to the next level by collecting data from all 20 total international student assessment tests encompassing some 78 countries and comparing them with measured IQ data from 128 countries. Rindermann finds, first of all that the combined national student results correlate perfectly with the combined national IQ data (.98), demonstrating the assessment scores and the IQ scores are the same measured construct. With all these diverse kinds of tests for each nation, Rindermann examines the data together through factor analysis and finds that the g factor of intelligence explains some 95% of the variance in the test results: "Thus, cognitive ability differences across nations are by and large unidimensional". (p 681) The stable differences between nations in all cognitive type tests are explained by the g factor.

Furthermore Rindermann emphasizes that, consistent with previous IQ testing, the g loaded international assessment tests reveal sub-Saharan African IQ scores that characteristically range from 1.5-2.5+ standard deviations below European and East Asian norms:
... I do not believe that the [sub-Saharan testing] scores at the general level are largely incorrect: The low values correspond to too many other variables and aspects standing for low cognitive abilities like results of student assessment and Piaget studies (e.g. Botswana in IEA-Reading 14 year-old pupils 1991 330, as IQ 75; South-Africa in TIMSS 8th graders 1999 259, as IQ 64; Ghana in TIMSS 8th graders 2003 266, as IQ 65; South-Africa in TIMSS 8th graders 2003 254, as IQ 63; plausibility considerations lead to lower results for the youth of Africa because of low school attendance rates and unrepresentative participation of countries), poor quality school systems, high skipping rates, low rates of high school degrees, low patent application rates, no famous universities, and many reports of everyday behaviour from officials, traders, journalists, ethnologists and other scientists in 19th century to this day... (p 770)

Thus typical African IQ scores of 70 and below can still be taken as a reliable finding. It is not simply the manufactured data of racialist researchers, or a byproduct of inadequate testing procedures. And, more importantly from the standpoint of the Watson controversy, certainly no reliable body of evidence has shown anything like parity with typical European scores.

I'd like to reiterate, then, that IQs below 70 do not by themselves signify mental retardation, as it is commonly understood as a pathological state.

There are two types of retardation: familial and organic. The former is caused by normal population variation in intelligence while the latter is caused by diverse individual problems such as genetic defects or head injuries. Related to this, the IQ scores of people with familial retardation correlate normally with their parent and sibling's IQ scores (.50), while the IQ scores of people with organic retardation are not much associated with the IQs in their family.

Retardation is measured by a combination of IQ and adaptive scales. Sometimes an IQ of 70 is used as the threshold of retardation. People with familial retardation and organic retardation of matched IQ perform the same in academic and training contexts, but organically retarded individuals do worse on the adaptive scales which measure things such as self-care, motor skills, and social functioning, signifying a broader range of mental dysfunction and some sort of developmental damage.

In the US, consistent with the normal bell curve, there are proportionately about five times as many blacks (16%) with an IQ of 70 or below than there are whites (3%). But basically the same proportional number of whites and blacks are organically retarded (whites 1.5%, blacks 2.0%). (The g Factor, p 369)

The African scores indicate that there are proportionately about seventeen times as many sub-Saharan Africans with IQs below 70 (50%) than American whites (3%), and possibly even more. While organic retardation is probably somewhat higher among Africans, due to overall more challenging health conditions, this should in no way be regarded as characteristic of their normal intelligence variation.

There is nothing particularly meaningful or necessary about an IQ of 70 as a threshold for 'retardation'. La Griffe Du Lion writes:
In 1959, [the American Association on Mental Deficiency] set the IQ threshold for mental retardation at 85. The civil rights movement of the next decade forced psychologists to rethink this boundary, because half the African American population fell below it. In 1973, responding to this concern, AAMD (by then AAMR) changed the threshold for retardation from IQ 85 to IQ 70. The boundary moved south by one standard deviation! The proportion of blacks below the threshold instantly dropped from about 50 percent to 12 percent.

In other words 50% of modern Africans are no more 'mentally retarded' than 50% of African-Americans were 'mentally retarded' in the 1960s. These are labels of convenience designed for normal within-population variation. But the real world academic and economic consequences of IQs of 70-85 and below are the same no matter what you label them.



Groups of people may differ genetically in their average talents and temperaments ... proponents of ethnic and racial differences in the past have been targets of censorship, violence, and comparisons to Nazis. Large swaths of the intellectual landscape have been reengineered to try to rule these hypotheses out a priori (race does not exist, intelligence does not exist, the mind is a blank slate...)
Steven Pinker - The Edge Annual Question - 2006. "What is your dangerous idea?"

Of course pointing to the testing data alone is hardly sufficient to quell these latter-day inquisitors. There is, sadly, an infinite regress of obscurantist objections designed to intellectually moot these issues entirely. These objections are not scientific, and are at odds with the data, logic, and, more often, both.

Systematic media misrepresentations of psychometric science have been occurring for going on 40 years.

In 1988 Stanley Rothman and Mark Snyderman published The IQ Controversy, the Media and Public Policy. Along with data from their 1987 study of over 1000 scholars in fields familiar with IQ testing, such as psychology, sociology, and behavioral genetics, Rothman and Snyderman took a quantitative look at media coverage of IQ and demonstrated how this media coverage habitually diverged with mainstream scholarly opinion.

This is particularly egregious during times of IQ controversy.

Media reports and editorials were quick to attack Watson on the premise that any statement about intelligence measures is scientifically indefensible, because science cannot study something so immeasurable and indefinable as intelligence. Cornelia Dean reporting for the New York Times did just this:
[T]here is wide disagreement about what intelligence consists of and how - or even if - it can be measured in the abstract.

Laura Blue in Time Magazine asserted:
... science has no agreed-upon definition of "intelligence" either - let alone an agreed-upon method to test it. All kinds of cultural biases have been identified in IQ tests, for example. If there is something fundamental in our brains that regulates our capacity to learn, we have yet to separate its effects from the effects of everything that we experience after we're born.

Similarly, Steven Rose in the New Statesmen:
... the question of what constitutes 'intelligence' is itself problematic - the word has much broader and diverse meanings than what can be encompassed in IQ tests.

Robert Sternberg in the Chicago Tribune:
Sternberg, a critic of traditional intelligence testing, believes intelligence can mean something different for different cultures. In parts of Africa, a good gauge of intelligence might be how well someone avoids infection with malaria -- a test of cleverness that most Americans likely would flunk.

In the same way, for many Africans who take Western IQ tests, "our problems aren't relevant to them," Sternberg said."

First of all, an intelligence test cannot and is not designed to tell you the reasons people score differently. So the fact that the test by itself has nothing to say about genetics is not a failure of the test. Second, the assertion of widespread chaos within science over intelligence is false. The statement that there are a number of theoretical differences about the concept of intelligence is only trivially true. In the practical context of research, provisional understanding, and 'normal science' this is rhetorically equivalent to underlining evolution as "only a theory" in media reports. Intelligence as a working scientific research concept and tool is both widespread (as a search for terms such as 'IQ', 'Intelligence' or 'cognitive ability' on PubMed, Google Scholar, or similar publication databases will show), and broadly consistent in approaches and shared theory, methods, premises, and data. The American Psychological Association's 11 member 'taskforce', assembled for a consensus statement on intelligence research, reported:
... [M]uch of our discussion is devoted to the dominant psychometric approach, which has not only inspired the most research and attracted the most attention (up to this time) but is by far the most widely used in practical settings.

Third, "All kinds of cultural biases" certainly have not been reported in IQ tests. The tests are not "biased" in the sense that psychometricians use this term. Again the APA taskforce showed consensus on this issue:
... the relevant question is whether the tests have a "predictive bias" against Blacks, Such a bias would exist if African-American performance on the criterion variables (school achievement, college GPA, etc.) were systematically higher than the same subjects' test scores would predict. This is not the case. The actual regression lines (which show the mean criterion performance for individuals who got various scores on the predictor) for Blacks do not lie above those for Whites; there is even a slight tendency in the other direction (Jensen, 1980; Reynolds &:Brown, 1984). Considered as predictors of future performance, the tests do not seem to be biased against African Americans.

Similarly Robert Sternberg argues that the tests are biased because they allegedly don't measure the sorts of abilities that are necessary for Africans to succeed in their unique environmental niche. This statement is not only a patronizing and idyllic caricature of African needs, but is also empirically false. This idea was addressed by psychologist Earl Hunt in his peer commentary on Rindermann:
There are two reasons that national-level differences in intelligence have been disregarded. One is that it can be argued that intelligence, as evaluated by these tests, is a Western concept, and that the abilities evaluated by the tests may not be the ones valued by non-western societies. This is a spurious argument for two reasons. First, the economic indicators we are trying to relate to intelligence are also Western concepts. As the commentator Thomas Friedman has said, the world is flat. We are not asking whether or not various national populations have the ability to compete in their own societies, we are asking about their ability to compete in the Western-defined international marketplace. The tests are appropriately designed to address this question. (p 727)

In fact, economists Eric A. Hanushek and Ludger Woessmann report that the association between economic outcomes and measured intelligence appear to be even higher within developing African countries than within Western countries. (pp 13-15) Similarly, at the national level, psychologists Earl Hunt and Werner Wittmann found that the relationship between GDP and national average IQ was stronger for the mostly African developing countries than it was among the developed industrial countries. (0.70 vs 0.58)

In their literature review, Kendall, Verster, and Von Mollendorf found that correlations between employee performance and educational outcomes and cognitive ability did not differ for blacks and whites in Southern Africa. In other words, at school or on the job, an African white with an IQ score of 70 will perform no different than an African black with the same score. Similarly an African black with an IQ of 115 performs the same as an African white with the same score.

So "our problems" certainly are relevant to Africans, and certainly are "their" problems. Unless issues such as child mortality, health, sanitation, rule of law, political stability, material comfort, global influence, and life expectancy are somehow not relevant to Africans.

Appearances to the contrary, the mendacious Robert Sternberg is, in fact, implicitly agreeing with Watson, while nevertheless shouting him down in the media. Sternberg does not deny that psychometric general intelligence is as low as reported in Africa, nor does he deny that this psychometric intelligence has the academic and economic consequences that the "racist... know-nothing" Watson implied it did. In fact, Sternberg himself has conducted intelligence studies in East Africa, and found the same characteristically 70ish IQ scores, as well as correlations between IQ and academic achievement in this region similar to the correlations reported in developed countries. Thus Sternberg's reply to Watson in The New Scientist:
The tests as they stand show some differences between various groups of children. The size of the differences and what groups do best in the tests depend on what is tested. For example, with various collaborators I have found that analytical tests of the kind traditionally used to measure so-called general abilities tend to favour Americans of European and Asian origin, while tests of creative and practical thinking show quite different patterns. On a test of oral storytelling, for example, Native Americans outperform other groups.

Ok, so Sternberg agrees that people of European and Asian descent do better on the analytical and general ability tests that reflect the skills vital for functioning in a first-world globalized economy, and therefore must be claiming that Watson is a racist ignoramus only for privileging these general abstract reasoning abilities with the designation of 'intelligence' over the 'oral storytelling intelligence' of Native-Americans, or the 'mosquito dodging intelligence' of sub-Saharan Africans! But if oral storytelling or mosquito dodging are not useful "intelligences" for lifting an individual or a nation out of 1 dollar a day poverty, then Watson can hardly be faulted for expressing concern about the kinds of intelligence not abundant in Africa.

Sternberg is perhaps the most blameworthy scientist to publicly condemn Watson, because he is familiar enough with the data to know Watson is right. His condescending statement that dodging mosquitoes is what characterizes the extent of African needs, is itself seemingly more "racist" than, if not completely identical in substance to, what Watson said. At least Watson appeared to show some sort of concern for what Africans countries require to industrialize, while Sternberg appears to be relativistically dismissing there are problems at all: "Africans are perfectly intelligent... for living like Africans!"

Actually, I believe Sternberg is taking the stage to condemn the factually correct Watson for his own petty academic reasons: Sternberg believes his own unpopular 'practical intelligence' (PDF) model could become more popular if the dominant psychometric model becomes increasingly professionally and personally dangerous to touch. Like Howard Gardner's empirically unimpressive 'Multiple Intelligences', there is an intellectual market for politically correct ideas like Sternberg's model, and fanning the flames of controversy around psychometrics is one way these ideas can cheat to become more popular.

Media red herrings about the supposed ineffability of intelligence or lies about the scientific worthlessness of intelligence testing are designed to moot honesty and openness on this issue, and simply side step the uncomfortable facts. But avoiding facts does not change reality or help shape it to our liking. Intelligence measures predict the kind of social and personal outcomes that people the world over agree are important and desirable. For this reason we need to start engaging this data instead of shooting the messengers. Especially when the messengers we are so casually discarding are important figures like James Watson.



Population genetics now provides a set of reasonably powerful statistical tools that allow us to determine whether... genes that play a role in the brain evolve much faster in certain human races than in others... The answers to such questions could clearly be awkward, if not incendiary... [O]ne of the most obvious questions about population genetic studies of human beings, especially human races [is s]hould they be performed?... The interesting point - and it's not widely appreciated - is that this question is rapidly becoming moot. Vast quantities of information about the human genome now pour into publicly available databases on a daily basis. These data are collected with the noblest of intentions (often medical) and are also made public for perfectly good reasons: citizens should have ready access to the fruits of publicly funded science. Indeed it's almost impossible to imagine how one could stop the sorts of studies I described above. In previous times, granting agencies, such as the NIH or NSF, could block funding for undesirable experiments or scientific journals could refuse to publish them. But with genomic data, minimal money is required (an Internet connection is enough) and any bright graduate student working in his parents' garage could ask and answer any awkward question he likes. And the Internet thoroughly dashes any chance of preventing the publication of unpleasant results.
H. Allen Orr - 'Talking Genes', The New York Review of Books.

Ubiquitous and prepackaged media tropes about race, perhaps more than intelligence, serve not as rational arguments but as apotropaic charms to ward off inconvenient ideas.

Laura Blue in Time Magazine asserted:
... [T]here is no scientific basis for [Watson's comments] ... For one thing, science has no agreed-upon definition of "race": however you slice up the population, the categories look pretty arbitrary.

Steven Rose in the New Statesman wrote:
Second, the idea that there is a genetically meaningful African 'race' is nonsense. There is wide cultural and genetic diversity amongst African populations from south to north, from Ethiopians to Nigerians. There are, for example probably genetic as well as environmental reasons why Ethiopians make good marathon runners whereas Nigerians on the whole do not.

To group the entire diverse populations of Africa together is a characteristically racist trick.

The Guardian reported:
Other scientists point out that our species is so young - Homo sapiens emerged from its African homeland only 100,000 years ago - that it simply has not had time to evolve any significant differences in intellectual capacity as its various groups of people have spread round the globe and settled in different regions. Only the most superficial differences - notably skin colour - separate the world's different population groupings. Underneath that skin, people are remarkably alike.

The Chicago Tribue reported:
Damaging statements such as Watson's -- and the potential for misuse of research on race -- has led many scientists to avoid the topic altogether. In a 1998 "Statement on 'Race,'" the American Anthropological Association concluded that ordinary notions of race have little value for biological research in part because of the relatively minor genetic differences among racial groups.

Craig Venter offered this rebuttal to Watson:
As Craig Venter, who pioneered much of America's work in decoding the human genome, put it: 'There is no basis in scientific fact or in the human gene code for the notion that skin colour will be predictive of intelligence.'

And our friend Robert Sternberg similarly added:
... [T]here is nothing special about skin colour that serves as a basis for differentiating humans into so-called races... Curiously, we do not apply the concept of "race" to colours of dogs or cats... [These] problems with our understanding of ... race show that the criticism being levelled at Watson is based on science rather than political correctness... race is a socially constructed concept, not a biological one.

Well, it's good to see that Venter and Sternberg are basing their criticisms on SCIENCE instead of political correctness! Of course the purposefully obscurantist conflation between 'skin color' and ancestry is something I've dealt with before.


These individuals would not be classified by geneticists, sociologists, psychologists, physical anthropologists, or any sort of scientist as members of the European race. They would not self-identify as white Americans, nor would they be considered as such. They would be eligible for affirmative action.

Human races, like dog 'breeds', are defined in the biological context by shared ancestry, not by single appearance traits. With ancestry you can predict many genes and many traits, but with single genes or single traits, you can not predict many other genes or traits. Which is why you can still easily identify the ancestry of the depigmented individuals in the above picture. Population ancestry predicts the sum patterns of one's genotype and phenotypical traits (e.g. general racial appearance) while any single variable - in this case, skin color - does not.

Denial of this fact was dubbed Lewontin's Fallacy (PDF) by British geneticist A.W.F. Edwards. 'Skin color' is a false and intentionally misleading straw-definition of race, that dishonorable public scientists such as Sternberg and Venter use to manufacture consent for their ideological viewpoints about human equality.

Steven Rose argues that the racial grouping 'sub-Saharan Africans' racistly lumps "diverse populations", but in the next breath uses such equally problematic and diversity encompassing racial categories as 'Nigerians' and 'Ethiopians'. And that is the problem with 'race' criticism, any population concept is diverse and fuzzy - German, Northwest European, New Yorker, Ashkenazi Jew, Asian - and yet the population concept is an essential cog in evolutionary science. The Neo-Darwinian Synthesis that grounded evolutionary theory in genetics, was the vital fusion of Darwin and population genetics. A population is a race is a population. To deny the population is literally a denial of evolution.

Race critics don't and could never explain satisfactorily why groupings like 'sub-Saharan Africans', 'Mediterranean', or 'Dutch' have no place in science, and more importantly the way scientists do use such groupings in practice belies the alleged uselessness (that is, like intelligence, the population concept clearly allows them to perform 'normal science'). And, yes, Dr. Rose, 'African' is a genetically meaningful entity:
In one of the most extensive of these studies to date, considering 1,056 individuals from 52 human populations, with each individual genotyped for 377 autosomal microsatellite markers, we found that individuals could be partitioned into six main genetic clusters, five of which corresponded to Africa, Europe and the part of Asia south and west of the Himalayas, East Asia, Oceania, and the Americas

You'll note, also, that this coauthor of the extreme anti-hereditarian tract Not In Our Genes also suggests marathon running ability in Ethiopia has a genetic component. This belief has become socially acceptable, but the evidence for genetic differences in population intelligence is hardly less spectacular than the evidence for this difference. I don't recall the large transracial adoption study that tested for marathon running. Each of these inferences can be based on the cross-cultural consistency and physiological correlates (PDF) of performance. It is ideology, not data, which keeps Rose from drawing the same inferences about the intelligence difference. It is also ideology that allows Rose to keep his job for this comment, while Watson lost his job for his substantively identical, yet socially taboo comment.

The claim that there has not been enough time for evolution to act on non-superficial traits is not scientific. First because nonsuperficial traits take no more time to evolve than superficial traits. More importantly, reasonable selection parameters allow for significant differences to arise between populations in 100 years, much less 100,000. Richard Lynn argues that genetics account for 1.3 SD in intelligence between sub-Saharan Africans and Europeans. Genetic anthropologist Henry Harpending illustrates how a 1 SD difference in a hypothetical trait, with a lower additive heritability than intelligence, could evolve in 500 years:
... [A]ssume time preference has an additive heritability of 25%. Assume that everyone with time preference more than 1 sd above the mean of the distribution has double the fitness of everyone else. About 16% of the population then has twice the number of offspring as everyone else on average.

After a generation of reproduction the new mean time preference will be increased by (0.2 * .25) or 5% of a standard deviation. In 20 generations, 500 years, time preference should go up by a full standard deviation.

This is similar to Cochran and Harpending's model (PDF) for the evolution of Ashkenazi intelligence. Also allowing for .5-1 SD higher intelligence in mere centuries.

Biologist Gerhard Meisenberg put it this way (PDF):
... the argument that the 100,000 years or so since the dispersal out of Africa were insufficient for the evolution of genetic differences is invalid. To create an IQ difference of, say, 15 points between two populations in 100,000 years, natural selection would have to drive their IQs apart by only 0.004 points every generation - about 1% of the selective pressure in late 20th-century America

Furthermore, is it true that races only differ in a few appearance related genes? Nope. We already have this data and it's not true by a long shot. Nick Wade reported early last year in the New York Times:
In a study of East Asians, Europeans and Africans, Dr. Pritchard and his colleagues found 700 regions of the genome where genes appear to have been reshaped by natural selection in recent times. In East Asians, the average date of these selection events is 6,600 years ago.

Many of the reshaped genes are involved in taste, smell or digestion, suggesting that East Asians experienced some wrenching change in diet. Since the genetic changes occurred around the time that rice farming took hold, they may mark people's adaptation to a historical event, the beginning of the Neolithic revolution as societies switched from wild to cultivated foods.

Some of the genes are active in the brain and, although their role is not known, may have affected behavior. So perhaps the brain gene changes seen by Dr. Pritchard in East Asians have some connection with the psychological traits described by Dr. Nisbett.

In fact, far from being identical, virtually all genes that are related to individual differences in human health and behavior differ to some degree in their frequency between racial populations. This is something you can and should test for yourself.

Gene Expression blogger p-ter recently wrote a very nice post titled So You Want to be a Population Geneticist. This is a How-2 for several genetic databases that can be used by anyone with an Internet connection to search for allele frequencies or signatures of selection. You can use these to look at the gene frequencies of the four population groups from the International HapMap Project: Utah whites, Nigerian Yoruba, Han Chinese, and Tokyo Japanese.

You'll note then that the International HapMap Project is designed to illuminate the genetic differences between these four "sliced-up", "arbitrary", "diverse", "genetically meaningless" racial populations, that are "defined by skin color". Didn't the HapMap people get the memo from SCIENCE that these categories are a racist biological fiction???

Go into Google News, and look under search terms like 'gene' and 'genes', and pick any random recent news items reporting an association between some gene/s and some sort of individual differences. This would not include studies that e.g. talk about genes that differentiate humans or chimpanzees, or that claim no individual differences.

Take the genes you find in the news and plug them into the HapMap Genome Browser , using p-ter's tips, and look how the frequencies differ. We even have an open thread for you to test your own hypotheses and report your findings from these databases. Unlike Watson's righteous regulators, we don't believe your hypotheses are immoral or "beyond the point of acceptable debate".

Posters on the Half Sigma blog recently used p-ter's post to see how CHRM2, a gene described as the first "yielding consistent evidence of association with IQ across multiple studies conducted by independent research groups", was distributed across the HapMap populations:
T is *way* more present than A in rs324650 among East Asians (91%) relative to Europeans (47%) and blacks (27%). Since T is associated with an increase in 4-5 points of performance IQ (what is that, anyway? Is that different from G?) that is significant.

The poster 'Marc' continued by examining how alleles differed for DTNBP1:
Let's look at rs:760761, rs:2619522 and rs:2619538, all of which are associated with increased or decreased intelligence in DTNBP1.

Regarding rs:760761, 18% of Europeans carry the T allele, which knocks about 8 points off the ol' IQ, compared to around 7% of East Asians and 37% of blacks.

Regarding rs:2619522, the numbers are similar. 18% of whites carry the G allele, which knocks about 7 points off the ol' IQ, versus around 8% of Asians and 35-36% of blacks...

Regarding rs:2619538, 61% of whites carry the T allele, which adds about 6.5 points to one's IQ, versus about 1% of Asians and 67% of blacks...

If 6% more blacks carry the T allele than whites (67% vs. 61%) on rs:2619538, and the T allele codes for 6.5 FSIQ (full scale IQ) points, then this gives blacks an advantage of .4 IQ points over whites from this SNP.

Also, if 60% more whites carry the T allele than Asians, and the T allele codes for 6.5 FSIQ points, than this gives whites an advantage of 3.9 IQ points over Asians from this SNP.

So the cumulative effect thus far would be:
minus 3.6 points for blacks relative to whites;
and minus 0.2 points for East Asians relative to whites.

A difference in one or two "intelligence genes" does not by itself suggest that one population is smarter than another, because evolutionary environments select for phenotypes not genotypes. So when populations have many genetic differences, the genes may interact in different ways, and some of the genes that make individuals more intelligent in one population may not have the same effect in another. (In other words if we'd prefer to not take the above results at face value, we have to accept that races are even more genetically different, not less)

However, several pieces of evidence make it doubtful that most intelligence genes are like this. For one, mixed race people generally have IQ scores about midway between their parent populations. (save one study of Eurasian mixes) So I would say the gradual accumulation of similar results for other "intelligence genes" would certainly serve as evidence for the genetic viewpoint.

These differences do illustrate, in yet another way, the falseness of popular arguments that races are genetically identical, or that genetic differences can somehow only exist for "appearance genes". But virtually any gene showing individual differences that you plug in those databases will also be distributed differently among racial groups and demonstrate the same points.



James Watson implied a belief that the uniquely low intelligence of both continental Africans and African-Americans are probably related to familiar genetic causes. This belief is deemed unacceptable to express in public, even in most academic contexts, or hold in private. This is despite the fact that the research evidence in support of this position is stronger than the research evidence that contradicts it. Thus even top scientists like Watson are punished for holding beliefs that are more scientific and logical, while scientists that hold to less scientific beliefs and illogical arguments are rewarded. This is a rot on the soul of science.

Many statements in the press asserted or implied that various environmental theories account for intelligence differences between ethnic groups. These statements do not, in fact, agree with the evidence.

The Chicago Tribune asserted:
The study of racial differences in IQ is among the most deeply contentious fields in all of science. Most researchers agree that tests have revealed some differences among racial groups -- but even larger differences between people of different income levels.

Steven Rose asserted:
Even where there are such average differences in IQ score, as for instance between Black and White populations in the US, there are no scientifically valid methods to enable one to untangle the many interacting factors of the validity of IQ tests themselves, as measures of anything other than school performance, educational and social deprivation, the history of slave-owners versus slaves and continuing racism, which may account for them.

The Associated Press reported:
Jan Schnupp, a lecturer in neurophysiology at Oxford University, said Watson's remarks "make it very clear that he is an expert on genetics, not on intelligence."

Schnupp said undernourished and undereducated people often perform worse on intelligence tests than the well off.

"Race has nothing to do with it, and there is no fundamental obstacle to black people becoming exceptionally bright," Schnupp said."

Contrary to the above claims, differences in intelligence between income groups are not larger than intelligence differences between racial groups in the US, nor do differences in income or wealth account for the racial differences. Whites from households in the lowest income bracket have higher IQ scores than blacks from households in the highest income bracket:
One of the most disturbing, I think perhaps the most disturbing fact in our whole book is that black students coming from families earning over 70,000 are doing worse on their SATS, on average--it's always on average--than white students from families in the lowest income group. You want to cry hearing that figure. I mean, it's so terrible.

One of the largest modern sociology studies of American students found that ethnicity was the single most important predictor of academic achievement:
Chin quotes with approval a book, "Beyond the Classroom," by Laurence Steinberg, B. Bradford Brown and Sanford M. Dornbusch, which says "of all the demographic factors we studied in relation to school performance, ethnicity was the most important. . . . In terms of school achievement, it is more advantageous to be Asian than to be wealthy, to have non-divorced parents, or to have a mother who is able to stay at home full time."

Contra Rose, a number of experiments are able to test all of these environmental theories. For one transracial adoption experiments control for all the shared aspects of the environment that differ between whites and blacks (parenting, income, nutrition, neighborhood), while structural equation models test for possible uncommon factors between whites and blacks that could be acting on IQ (which would include things like racism). These experiments do not lend support to any existing or plausible environmental theories for the remaining lower intelligence scores of people of African descent in Western societies. The Minnesota Transracial Adoption Study found that, by adulthood, the difference in IQ scores between adopted black and adopted white children raised side by side in the same high income households in mostly homogeneous Northern US upper class neighborhoods was 18 IQ points (p 185):

The Minnesota Transracial Adoption Study

IQ at Age 7        IQ at Age 17

W-W 111.5        W-W 101.5
W-B 105.4        W-B 93.2
B-B 91.4        B-B 83.7

W-W = Adopted children with two white biological parents.
W-B = Adopted children with one black and one white biological parent.
B-B = Adopted children with two black biological parents.

The W-W/W-B difference is 8.3 IQ points. The B-W/B-B difference is 9.5 IQ points. And the W-W/B-B difference is 17.8 IQ points.

The difference in IQ scores between 2 black biological parent adoptees and 1 black biological parent adoptees is nearly 10 IQ points despite the fact that both share the exact same social identity.

Similarly a dozen mixed race children that were raised under some mistaken information that they had two black biological parents nevertheless developed IQ scores like the other mixed race children.

There are no simple or plausible environmental theories to explain these kinds of findings.

An additional popular argument is that the Flynn Effect, the observed rise in IQ scores over time, is evidence that African-Americans or African countries will eventually reach parity with white norms. This typically includes the premise that white intelligence in the recent past was even lower than modern black intelligence. A typical example:
US Blacks, with an average IQ today of 85, have the same IQ as US Whites with an IQ of 100 in 1957. If 1957 US Whites were not stupid, then neither are US Blacks today. It's time to shut up about the "low Black IQ", since by any reasonable standard, it is not really low at all.

These arguments are wrong for the simple fact that the Flynn Effect is not a gain in real g factor intelligence, while the differences between nations and ethnic groups are differences in g factor intelligence. These findings led a 2004 team to state:
It appears therefore that the nature of the Flynn effect is qualitatively different from the nature of B-W [Black-White] differences in the United States... [so] implications of the Flynn effect for B-W differences appear small...

James Flynn, namesake of the secular increase, reiterates (DOC) these points:
Factor analysis is a way of measuring this tendency of some people to do better or worse than average across the board; and it yields something called g (a sort of super-correlation coefficient), which psychologists call the general intelligence factor...

When you analyze IQ gains over time, you often find that they do not constitute enhancement of these latent traits -- they do not seem to be general intelligence gains, or quantitative factor gains, or verbal factor gains (Wicherts et al, in press). In the language of factor analysis, this means that IQ gains over time tend to display 'measurement artifacts or cultural bias'. For a second time, we are driven to the conclusion that massive IQ gains are not intelligence gains or, indeed, any kind of significant cognitive gains. (pp 27-28)

Flynn believes the secular increase represents important changes in specific narrow aspects of developed cognitive style, but not a rise in g intelligence.

It is therefore incorrect that 1945 US whites were less intelligent than 2007 US blacks. The Flynn Effect has little apparent bearing on racial intelligence gaps.

This also applies to developing countries. The Flynn Effect reveals that IQ scores in the developed world were some 1.5-2 standard deviations lower in the beginning of the 20th century. (See this GNXP post for the data) These scores are similar to ones in modern African. Some studies also reveal even faster Flynn gains in developing countries than what we observe in developed countries, and it is argued these countries are simply experiencing, in slight delay, what happened in developed countries during the 20th century. But this interpretation is not tenable if there were no actual rises in g factor intelligence in developed countries. It is incorrect that developed countries had lower g intelligence in the first half of the 20th century corresponding to IQs of 70. Meanwhile, as the Rindermann paper reveals, the scores across modern nations do correspond to real intelligence differences. Likewise, extremely low IQ scores in modern Africa, unlike scores in developed countries prior to the mid-20th century, correspond to genuine deficits in g intelligence.

With improvements in nutrition it is likely that scores in Africa will rise over time. But these increases will probably be genuine and of a different nature than what we observed in developed countries. It is unlikely that scores in Africa will meet or rise above those of African-Americans in the next century.

All of this underlines the fact that IQ can't always be taken at face value. Gains or differences in IQ exceeding 1 SD can sometimes be 'hollow', or unreflective of real general intelligence, being manifested only at the lower order strata of intelligence. (See this paper examining how these false gains can arise through practice effects) Fortunately we have good methods for evaluating the construct validity of the tests and the integrity of the IQ scores.



Many intellectuals refuse to interpret psychometric claims or ideas about human diversity rationally. Despite 100 years of data showing that ethnic groups differ in their general intelligence, these claims are still rejected on moral grounds. Many of those who deny these claims either implicitly believe that 'intelligence' is a reflection of human worth, or believe any claim of such a difference must be a cryptic assertion of racial worth. Either way it prevents the claims from being interpreted fairly, in the factual, rather than normative, manner intended by the people who attempt to discuss this science in an open forum.

Watson's original statements about the lower general intelligence of Africans were interpreted as statements about the lower human worth of Africans. When Watson then publicly apologized that his words were being misinterpreted in this way and clarified that claims about racial intelligence differences are not claims about human worth, the confused media reported that Watson had recanted his claims about intelligence differences!!

The science journal Nature ran an editorial claiming:
Watson has apologized and retracted the outburst... He acknowledged that there is no evidence for what he claimed about racial differences in intelligence.

Time magazine also suggested he retracted his intelligence claims:
Watson said in a statement he issued at the Royal Society Thursday. "That is not what I meant. More importantly from my point of view, there is no scientific basis for such a belief."

And on that much at least, he's right. For one thing, science has no agreed-upon definition of "race": however you slice up the population, the categories look pretty arbitrary. For another, science has no agreed-upon definition of "intelligence" either

And Cornelia Dean at the New York Times asserted, not once, but in two separate reports that Watson retracted his intelligence claims. Even doctoring Watson's apology by cut-and-pasting together two entirely separate Watson quotes:
In an interview published Sunday in The Times of London, Dr. Watson is quoted as saying that while "there are many people of color who are very talented," he is "inherently gloomy about the prospect of Africa."

"All our social policies are based on the fact that their intelligence is the same as ours - whereas all the testing says not really," the newspaper quoted him as saying.

"I cannot understand how I could have said what I am quoted as having said," Dr. Watson said in a statement given to The Associated Press. "There is no scientific basis for such a belief."

And again in another article:
Dr. Watson... was quoted in The Times of London last week as suggesting that, overall, people of African descent are not as intelligent as people of European descent. In the ensuing uproar, he issued a statement apologizing "unreservedly" for the comments, adding "there is no scientific basis for such a belief".

False. False. False.

Dear media,

Please read the actual text of James Watson's apology printed in the Independent, instead of mangling it and interpolating it with your own claims:
To those who have drawn the inference from my words that Africa, as a continent, is somehow genetically inferior, I can only apologise unreservedly. That is not what I meant. More importantly from my point of view, there is no scientific basis for such a belief...

The overwhelming desire of society today is to assume that equal powers of reason are a universal heritage of humanity....

To question this is not to give in to racism. This is not a discussion about superiority or inferiority, it is about seeking to understand differences, about why some of us are great musicians and others great engineers.

Watson would only be retracting his intelligence claims if he considered those claims tantamount to claims of 'superiority' or 'inferiority', which he clearly emphasizes he doesn't. Watson is saying that questioning that all races are equal in intelligence is not racism, it is trying to figure out why the world looks the way it does, with the greatest engineers and the greatest musicians disproportionately coming, in a systematic way, from different racial backgrounds. In other words culturally separated people of African descent have been musical innovators across a diverse range of cultures (in the Middle East, Africa, Europe, North and South America, and the Caribbean), while culturally separated people of East Asian descent have excelled at math and science across a diverse range of cultures (in Asia, Europe, North and South America, and the Caribbean).

This is not a claim of racial 'superiority' or 'inferiority', either in terms of legal worth or even in terms of overall talent - since groups all have different strengths and weaknesses. It is simply the recognition that people of different genetic heritage, on average, reveal different talents wherever they are found in the world, and there is one explanation that best accounts for these observations: evolution.

In other words, Watson was thinking like a scientist. Which is exactly why he was punished.

The moral laws of our society dictate that we are not allowed to think scientifically about some issues. Especially not in public.



According to the media and members of the scientific community, James Watson hurt science itself.

An editorial in the top science journal Nature asserted:
Crass comments by Nobel laureates undermine our very ability to debate such issues, and thus damage science itself.

Similarly the Chicago Tribune featured this:
"The damage to Watson's legacy from his statements may be difficult to mend," said Jerry Coyne, a professor of evolutionary genetics at the University of Chicago.

"He's done tremendous damage to science, to himself and to social equality," Coyne said. "It makes us all look bad."

Along with E.O. Wilson, James Watson is perhaps the most distinguished living figure in American biology, and yet even he was not immune to immediate expulsion from the very lab he created and built up over 40 years of his life, and excommunication from the scientific establishment that celebrated him. All this for one crime: voicing scientific facts and hypotheses that made this community uncomfortable. The same personal and professional fate befell former Harvard president Larry Summers in 2005 for a purely academic discussion of females in science during an economics conference intended for discussing this very subject!

What effect will this continuing intellectual mob violence have on future and current scientists and researchers who want to freely study human genetics, cross-cultural psychology, sociology, or any discipline that may reveal similar facts that have the potential to cause their professional or personal destruction by an intellectual community that resembles the medieval church?

Those who punish, those who lie, those who silence, those who condemn, those who intimidate... they have corrupted science.

They have injured the intellectual openness, freedom, and fairness of our society and our institutions, with untold costs to our collective human well-being.

Not James D. Watson.




IQ: 64
Age: Adults
N: 80
Test: CPM
Ref: Berlioz, L. (1955). Etude des progressive matrices faite sur les Africains de Douala. Bulletin du Centre Etude Recherce Psychotechnique, 4, 33-44.

Equatorial Guinea
IQ: 59
Age: 10-14
N: 48
Test: WISC-R
Ref: Fernandez-Bellesteros, R., Juan-Espinoza, M., Colom, R., and Calero, M. D. (1997). Contextual and personal sources of individual differences in intelligence. In J. S. Carlson (Ed.), Advances in Cognition and Educational Practice. Greenwich, Cnn.: JAI Press.

IQ: 67
Studies: 4

IQ: 80
Age: Adults
N: 225
Test: CF
Ref: Buj, V. (1981). Average IQ values in various European countries. Personality and Individual Differences, 2, 168-169.

IQ: 62
Age: 15
N: 1,693
Test: CPM
Ref: Glewwe, P. and Jaccoby, H. (1992). Estimating the determinants of Cognitive Achievement in Low Income Countries. Washington, D.C.: World Bank.

IQ: 65 (266)
Age: 16
N: 5,100
Test: TIMSS 2003
Ref: Martin, M.O., Mullis, I.V.S., & Chrostowski, S.J. (Eds.) (2004). TIMSS 2003 Technical Report. Chestnut Hill, MA: TIMSS & PIRLS International Study Center, Boston College.

IQ: 67
TIMSS 2003: 266 (65)
TIMSS sum: 301
TIMSS+PIRLS sum: 304
Sum: 300

IQ: 67
Studies: 2

IQ: 63
Age: 5-14
N: 50
Test: AAB
Ref: Nissen, H. W., Machover, S. and Kinder, E. F. (1935). A study of performance tests given to a group of native African Negro children. British Journal of Psychology, 25, 308-355.

IQ: 70
Age: Adults
N: 1,144
Test: SPM
Ref: Faverge, J. M. and Falmagne, J. C. (1962). On the interpretation of data in intercultural psychology. Psychologia Africana, 9, 22-96.

IQ: 69
Studies: 5

IQ: 70
Age: Children
N: 480
Test: Leone
Ref: Farron, O. (1966). The test performance of coloured children. Educational Research, 8, 42-57.

IQ: 64
Age: Adults
N: 86
Test: SPM
Ref: Wober, M. (1969). The meaning and stability of Raven's matrices test among Africans. International Journal of Psychology, 4, 220-235.

IQ: 69
Age: 6-13
N: 375
Test: CPM
Ref: Fahrmeier, E. D. (1975). The effect of school attendance on intellectual development in Northern Nigeria. Child Development, 46, 281-285.

IQ: 79 (401)
Age: 15
N: 2,368
Test: IEA-R 1991
Ref: Elley, W. B. (1992). How in the world do students read? The Hague: IEA.

IQ: 69
ISARS: 34 (69)

Sierra Leone
IQ: 64
Studies: 2

IQ: 64
Age: Adults
N: 122
Test: CPM
Ref: Berry, J. W. (1966). Temne and Eskimo perceptual skills. International Journal of Psychology, 1, 207-229.

IQ: 64
Age: Adults
N: 33
Test: CPM
Ref: Binnie-Dawson, J. L. (1984). Biosocial and endocrine bases of spatial ability. Psychologia, 27, 129-151.

Burkina Faso
Cote d'Ivoire
The Gambia
Sao Tome and Principe


Democratic Republic of Congo
IQ: 65
Studies: 5

IQ: 64
Age: Adults
N: 67
Test: SPM
Ref: Verhagen, P. (1956). Utilite actuelle des tests pour l'etude psychologique des autochones Congolese. Revue de Psychologie Appliquee, 6, 139-151.

IQ: 68
Age: 10-15
N: 222
Test: SPM
Ref: Laroche, J. L. (1959). Effets de repetition du Matrix 38 sur les resultats d'enfants Katangais. Bulletin du Centre d’etudes et Reserches Psychotechniques, 1, 85-99.

IQ: 62
Age: 8
N: 47
Test: KABC
Ref: Boivin, M. J. and Giordani, B. (1993). Improvements in cognitive performance for schoolchildren in Zaire following an iron supplement and treatment for intestinal parasites. Journal of Pediatric Psychology, 18, 249-264.

IQ: 68
Age: 7-12
N: 95
Test: LABC
Ref: Boivin, M. J., Giordani, B., and Bornfeld, B. (1995). Use of the tactual performance test for cognitive ability testing with African children. Neuropsychology, 9, 409-417.

IQ: 65
Age: 7-9
N: 130
Test: KABC
Ref: Giordani, B., Boivin, M. J., Opel, B., Nseyila, D. N., and Lauer, R. E. (1996). Use of the K-ABC with children in Zaire. International Journal of Disability, Development, and Education, 43, 5-24.

Republic of Congo
IQ: 64
Studies: 3

IQ: 64
Age: Adults
N: 1,596
Test: SPM
Ref: Latouche, G. L. and Dormeau, G. (1956). La foration professionelle rapide en Afrique Equatoriale Francaise. Brazzaville: Centre d'Etude des Problems du Travail.

IQ: 64
Age: 17-29
N: 320
Test: SPM
Ref: Ombredane, A., Robaye, F., and Robaye, E. (1952). Analyse des resultats d'une application experimentale du matrix 38 a 485 noirs Baluba. Bulletin Centre d'etudes et Reserches Psychotechniques, 7, 235-255.

IQ: 73
Age: 8
N: 73
Test: SPM
Ref: Nkaye, H. N., Huteau, M., and Bonnet, J. P. (1994). Retest effect on cognitive performance on the Raven Matrices in France and in the Congo. Perceptual and Motor Skills, 78, 503-510.

Central African Republic
IQ: 64
Age: Adults
N: 1,149
Test: SPM
Ref: Latouche, G. L. and Dormeau, G. (1956). La foration professionelle rapide en Afrique Equatoriale Francaise. Brazzaville: Centre d'Etude des Problems du Travail.



IQ: 71
Studies: 4

IQ: 69
Age: 7-16
N: 291
Test: Various
Ref: Fahmy, M. (1964). Initial exploring of the intelligence of Shilluk children. Vita Humana, 7, 164-177.

IQ: 64
Age: 6
N: 80
Test: DAM
Ref: Badri, M. B. (1965a). The use of finger drawing in measuring the Goodenough quotient of culturally deprived Sudanese children. Journal of Psychology, 59, 333-334.

IQ: 74
Age: 9
N: 292
Test: DAM
Ref: Badri, M. B. (1965b). Influence of modernization on Goodenough quotients of Sudanese children. Perceptual and Motor Skills, 20, 931-932.

IQ: 72
Age: 8-12
N: 148
Test: SPM
Ref: Ahmed, R. A. (1989). The development of number, space, quantity, and reasoning concepts in Sudanese schoolchildren. In L. L. Adler (Ed.), Cross Cultural Research in Human Development. Westport, Conn.: Praeger.

IQ: 72
Studies: 6

IQ: 69
Age: Adults
N: 205
Test: CPM
Ref: Boissiere, M., Knight, J. B., and Sabot, R. H. (1985). Earnings, schooling, ability, and cognitive skills. American Economic Review, 75,1016-1030.

IQ: 75
Age: 6-10
N: 1,222
Test: CPM
Ref: Costenbader, V. and Ngari, S. M. (2000). A Kenya standardisation of the Coloured Progressive Matrices. School Psychology International, 22, 258-268.

IQ: 69
Age: 12-15
N: 85
Test: CPM-MH
Ref: Sternberg, R. J., Nokes, C., Geissler, P. W., Prince, R., Okatcha, F., Bundy, D. A., and Grigorenko, E. L. (2002). The relationship between academic and practical intelligence: A case study in Kenya. Intelligence, 29, 401-418.

IQ: 76
Age: 7
N: 118
Test: CPM
Ref: Daley, Y. C., Whaley, S. E., Sigman, M. D., Espinosa, M. P., and Neuman, C. (2003). IQ on the rise: the Flynn effect in rural Kenyan children. Psychological Science, 14, 215-219.

IQ: 89
Age: 7
N: 537
Test: CPM
Ref: Daley, Y. C., Whaley, S. E., Sigman, M. D., Espinosa, M. P., and Neuman, C. (2003). IQ on the rise: the Flynn effect in rural Kenyan children. Psychological Science, 14, 215-219.

IQ: 63
Age: 6
N: 184
Test: KABC
Ref: Holding, P. A., Taylor, H. G., Kazungu, S. D., and Mkala, T. (2004). Assessing cognitive outcomes in a rural African population: development of a neuropsychological battery in Kilifi district. Journal of the International Neuropsychological Society, 10, 246-260.

IQ: 72
Studies: 3

IQ: 78
Age: 13-17
N: 2,959
Test: SPM
Ref: Klingelhofer, E. L. (1967). Performance of Tanzanian secondary school pupils on the Raven Standard Progressive Matrices test. Journal of Social Psychology, 72, 205-215.

IQ: 65
Age: Adults
N: 179
Test: CPM
Ref: Boissiere, M., Knight, J. B., and Sabot, R. H. (1985). Earnings, schooling, ability,and cognitive skills. American Economic Review, 75,1016-1030.

IQ: 72
Age: 11-13
N: 458
Test: WCST
Ref: Sternberg, R. J., Grigorenko, E. L., Ngorosho, D., Tantufuye, E., Mbise, A., Nokes, C., Jukes, M., and Bundy, D. A. (2002). Assessing intellectual potential in rural Tanzanian school children. Intelligence, 30, 141-162.

IQ: 73
Age: 11
N: 2,019
Test: RPM
Ref: Heyneman, S. P. and Jamison, D. T. (1980). Student learning in Uganda. Comparative Education Review, 24, 207-220.

IQ: 64
Studies: 2

IQ: 65
Age: 15
N: 250
Test: SPM
Ref: Lynn, R. (1994). The intelligence of Ethiopian immigrant and Israeli adolescents. International Journal of Psychology, 29, 55-56.

IQ: 63
Age: 14-16
N: -
Test: SPM
Ref: Kazulin, A. (1998). Profiles of immigrant students' cognitive performance on Raven's Progressive Matrices. Perceptual and Motor Skills, 87, 1311-1314.



IQ: 76
Studies: 2

IQ: 77 (366)
Age: 15
N: 5,150
Test: TIMSS 2003
Ref: Martin, M.O., Mullis, I.V.S., & Chrostowski, S.J. (Eds.) (2004). TIMSS 2003 Technical Report. Chestnut Hill, MA: TIMSS & PIRLS International Study Center, Boston College.

IQ: 75 (330)
Age: 15
N: 4,768
Test: IEA-R 1991
Ref: Elley, W. B. (1992). How in the world do students read? The Hague: IEA.

TIMSS sum: 396
TIMSS+PIRLS sum: 398
Sum: 391

IQ: 62
Studies: 2

IQ: 64
Age: 20
N: 149
Test: CPM
Ref: Kendall, I. M. (1976). The predictive validity of a possible alternative to the Classification Test Battery. Psychologia Africana, 16, 131-146.

IQ: 60
ISAMS: 24 (60)

South Africa (blacks)
IQ: 67
Studies: 13

IQ: 63
Age: 9
N: 350
Test: SPM
Ref: Lynn, R. and Holmshaw, M. (1990). Black-white differences in reaction times and intelligence. Social Behavior and Personality, 18, 299-308.

IQ: 67
Age: 8-10
N: 806
Test: CPM
Ref: Jinabhai, C. C., Taylor, M., Rangongo, N. J., Mkhize, S., Anderson, S., Pillay, B. J., and Sullivan, K. R. (2004). Investigating the mental abilities of rural primary school children in South Africa. Ethnicity and Health, 9, 17-36.

IQ: 67
Age: 14-17
N: 152
Test: WISC-R
Ref: Skuy, M., Schutte, E., Fridjhon, P., and O'Carroll, S. (2001). Suitability of published neuropsychological test norms for urban African secondary school students in South Africa. Personality and Individual Differences, 30, 1413-1425.

IQ: 65
Age: 10-12
N: 293
Test: AAB
Ref: Fick, M. L. (1929). Intelligence test results of poor white, native (Zulu), colored, and Indian school children and the social and educational implications. South Africa Journal of Science, 26, 904-920.

IQ: 75
Age: 8-16
N: 1,008
Test: SPM
Ref: Notcutt, B. (1950). The measurement of Zulu intelligence. Journal of Social Research, 1, 195-206.

IQ: 69
Age: Adults
N: 153
Test: WAIS-R
Ref: Nell, V. (2000). Cross-Cultural Neuropsychological Assessment. Mahwah, NJ: Lawrence Erlbaum.

IQ: 64
Age: Adults
N: 703
Test: SPM
Ref: Notcutt, B. (1950). The measurement of Zulu intelligence. Journal of Social Research, 1, 195-206.

IQ: 71
Age: Adults
N: 140
Test: WISC-R
Ref: Avenant, T. J. (1988). The Establishment of an Individual Intelligence Scale for Adult South Africans. Report No. P-91. Pretoria: Human Sciences Research Council.

IQ: 68
Age: 15-16
N: 1,093
Test: JAT
Ref: Lynn, R., and Owen, K. (1994). Spearman's hypothesis and test score differences between whites, Indians and blacks in South Africa. Journal of General Psychology, 121, 27-36.

IQ: 63
Age: 16
N: 1,096
Test: SPM
Ref: Owen, K. (1992). The suitability of Raven's Progressive Matrices for various groups in South Africa. Personality and Individual Differences, 13, 149-159.

IQ: 64 (259)
Age: 16
N: 8,146
Test: TIMSS 1999
Ref: Martin, M. O., Gregory, K. D., & Stemler, S. E. (Eds.) (2000). TIMSS Technical Report: IEA's Third International Mathematics and Science Study at the Eighth Grade (Boston, Intrenational study Center, Boston College).

IQ: 63 (254)
Age: 15
N: 8,952
Test: TIMSS 2003
Ref: Martin, M.O., Mullis, I.V.S., & Chrostowski, S.J. (Eds.) (2004). TIMSS 2003 Technical Report. Chestnut Hill, MA: TIMSS & PIRLS International Study Center, Boston College.

IQ: 69
TIMSS 1995: 270
TIMSS 1999: 259 (64)
TIMSS 2003: 254 (63)
TIMSS sum: 304
TIMSS+PIRLS sum: 328
Sum: 324

IQ: 64
ISAMS: 32 (64)

IQ: 71
Studies: 2

IQ: 77
Age: 13
N: 759
Test: SPM
Ref: MacArthur, R. S., Irvine, S. H., and Brimble, A. R. (1964). The Northern Rhodesia Mental Ability Survey. Lusaka: Rhodes Livingstone Institute.

IQ: 64
Age: Adults
N: 152
Test: SPM
Ref: Pons, A. L. (1974). Administration of tests outside the cultures of their origin. 26th Congress of the South African Psychological Association.

IQ: 70
Studies: 3

IQ: 61
Age: 12-14
N: 204
Test: WISC-R
Ref: Zindi, F. (1994). Differences in psychometric performance. The Psychologist, 7, 549-552.

IQ: 70
Age: 12-14
N: 204
Test: SPM
Ref: Zindi, F. (1994). Differences in psychometric performance. The Psychologist, 7, 549-552.

IQ: 76 (372)
Age: 16
N: 2,749
Test: IEA-R 1991
Ref: Elley, W. B. (1992). How in the world do students read? The Hague: IEA.


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Wednesday, October 17, 2007

Human variation in Nature   posted by Razib @ 10/17/2007 11:09:00 AM

Nice little article in Nature. Here's the conclusion:
"This is a very delicate time, and a dangerous time, as people start to come up with things that the general public, or the media, or various groups might misinterpret," Sabeti says. "I like the fact that, so far, the evidence we find for natural selection in humans is only skin deep."

Here's an interview with Pardis Sabeti (she is also the first speaker at this 2006 "Inspiration Festival" sponsored by Seed). She is lead author on Genome-wide detection and characterization of positive selection in human populations in the current issue of Nature (step away from the computer Assman....).


Tuesday, October 16, 2007

Is James Watson a racist?   posted by Razib @ 10/16/2007 10:06:00 PM

Africans are less intelligent than Westerners, says DNA pioneer:
The 79-year-old geneticist reopened the explosive debate about race and science in a newspaper interview in which he said Western policies towards African countries were wrongly based on an assumption that black people were as clever as their white counterparts when "testing" suggested the contrary. He claimed genes responsible for creating differences in human intelligence could be found within a decade.

The newly formed Equality and Human Rights Commission, successor to the Commission for Racial Equality, said it was studying Dr Watson's remarks "in full". Dr Watson told The Sunday Times that he was "inherently gloomy about the prospect of Africa" because "all our social policies are based on the fact that their intelligence is the same as ours - whereas all the testing says not really". He said there was a natural desire that all human beings should be equal but "people who have to deal with black employees find this not true".

His views are also reflected in a book published next week, in which he writes: "There is no firm reason to anticipate that the intellectual capacities of peoples geographically separated in their evolution should prove to have evolved identically. Our wanting to reserve equal powers of reason as some universal heritage of humanity will not be enough to make it so."


1) This isn't surprising coming from Watson. He has a long track record (one story from someone who has done research at Cold Harbor is just that, but many is a trend).

2) I'll be interested in seeing what he says in the book. I hope it is a bit more nuanced, seeing as not everyone in the First World is the same race. There are some black and brown people who are citizens of Western nations after all! Does his "our" include us? Who exactly is we Dr. Watson?

3) There are sensitive topics that are best spoken of clinically, bandying about anecdotes about black employees really won't cut it. That's low hanging fruit for Steve Rose. Seriously.

4) That being said, Watson is not a racialist, just as W.D. Hamilton was not racialist. He's just really blunt (or stupid or off his meds depending on how you look at it) and he is offering his opinion on what he believes to be the most parsimonious explanation for the variation he sees in the world out there. Is he wrong? Is he too much of a geneticist so that there is always nail ready for his hammer? Perhaps. I've said as much about W.D. Hamilton. Nevertheless, Watson's views aren't that exceptional. There are many other biologists who would view Watson's evaluation of the issues in regards to intergroup differences as reasonable, whether they agree with him or not. Not because they have a particular racialist impulses, but because evolutionary biology implies the plausibility of human variation on a host of traits. Including behavioral and cognitive traits.

5) A snip from the article:
Steven Rose, a professor of biological sciences at the Open University and a founder member of the Society for Social Responsibility in Science, said: "This is Watson at his most scandalous. He has said similar things about women before but I have never heard him get into this racist terrain. If he knew the literature in the subject he would know he was out of his depth scientifically, quite apart from socially and politically."

Ah, alas, the time for show trials is over comrade Rose. Now, here is something to repeat five times before breakfast: legal equality is not contingent upon biological equality, is does not necessarily imply ought and natural does not necessarily imply good. These are old lessons, centuries old, but it maybe that we have to learn these simple lessons again in the interests of a liberal order. What we hold to be good, true and right is not good, true and right because the world is as it is, but because it is what we wish it to be. And for us to most efficiently attain what we wish we must wrestle what what is. Live not for the fashions of the day, honor the timeless truths of nature.

Addendum: Watson's new book is titled Avoid Boring People. Well, at least he's trying to contribute to the trend he's promoting.

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Friday, October 12, 2007

Blondism in Melanesia   posted by Razib @ 10/12/2007 01:01:00 AM

The photo to the left is of a girl from Malaita in the Solomon Islands (Photo credit: Jonathan Friedlaender). The Solomons are in the heart of Melanesia, the "black islands." When I was a small child looking through anthropological books I would on occasion stumble upon photographs of very dark-skinned people from Oceania with light hair. Invariably they would not be light-brown Polynesians, but extremely dark Melanesians. You see references to this in C.S. Coon's old books as well. I've been digging for a few years into the nature of the trait of blondism in this part of the world, and I've come upon an interesting paper, Skin and hair pigmentation variation in Island Melanesia. Below the fold there is a map I've cut out of the skin & hair pigmentation.

I'm intrigued by #27 on Bougainville, the Aita. From the text:
An interesting hair phenotype that is sometimes seen in Island Melanesia (as well as among Australian Aborigines) is "blondism," in which individuals exhibit the characteristic darkly pigmented skin of the region while also having blond hair. This trait was most commonly observed in children whose hair generally darkened around puberty (Robins, 1991). However, in some cases, blondism persists into adulthood, although the hair appears somewhat darker than what is seen in children. The strikingly light hair of the partially due to the high incidence of blondism among this group.

So who are the Aita? They're an isolated "Papuan" group. In the context of Melanesia the appellation Papuan is simply a catchall for the host of ancient peoples who were extant in the region before the expansion of Austronesians within the last 5,000 years. Could the blondism be due to European admixture? From the text:
The Aita live in an isolated mountainous region of northern Bougainville, and although the Ane'm had recently moved down to the coast they were originally an inland rather than shore-based group. It may be that the resistance of coastal groups to intermarriage with supposedly "darker" populations such as the Aita or Ane'm is really reflective of resistance to intermarriage with inland populations that are generally considered less sophisticated. Whatever the reason, this resistance may help strengthen the genetic differences observed between coastal and inland groups.

The median skin color on Bougainville is amongst the darkest in the world, and the Aita are reputed to be among the darker residents of Bougainville. Additionally there is no report of blue eyes amongst these Melanesian peoples, which in Europeans is more common than blonde hair. Two papers, Melanesian mtDNA Complexity and Unexpected NRY Chromosome Variation in Northern Island Melanesia, shed some light on the genetic relationship of the Aita to the other groups in the region. They are it seems an ancient and rather isolated people who are geneticallyhomogeneous in a region characterized by a great deal of between group genetic variation. I am willing to hazard that presence of blondism in Melanesia is a function of the diversity of the region and its relative insulation from demographic sweeps which characterized much of the rest of the world. The Austronesians brought a more advanced culture and acculturated the coastal groups, but the ecology of Melanesia allowed the indigenous peoples, those termed Papuans, to maintain their existence inland. The high frequencies of an anomolous trait such as blondism among the Aita may simply be due to genetic drift through a population bottleneck.

But a more curious question is the genetic architecture of blondism among these groups. The peoples of Bougainville are known to be functionally constrained in regards the genes which are implicated in controlling skin color variation. From Signatures of positive selection in genes associated with human skin pigmentation as revealed from analyses of single nucleotide polymorphisms:
Our results showed that African populations tended to carry the ancestral alleles of the studied SNPs...and that human populations with dark skin colour tended to cluster together in the MDS and STRUCTURE analyses. The clustering of the Bougainville Islander population reflects the fact that this relationship is not (or at least not solely) caused by geography but also by the underlying pigmentation genes. Bougainville Islanders from Papua New Guinea are known to be one of the most highly pigmented people in the world...In our results they appeared to be closer to Sub-Saharan Africans populations - with whom they share the dark skin colour phenotype - than to the second Papuan New Guinea sample in the dataset, with whom they share their recent population history, as observed in several datasets based on neutral genetic variation from autosomal, Y-chromosomal and mtDNA analyses....

So how are they blonde? The genes which seem to control variation in human skin color seem to have some effect on hair color. Blondism in Europeans is simply due to low levels of eumelanin (brown) and pheomelanin (reddish), and the darkening of skin naturally has a tendency to upregulate the production of melanin globally so as to darken hair. How can the peoples of Bougainville retain dark skin while selectively downregulating the production to their hair? Well, we know that the region around OCA2 is implicated in a quasi-Mendelian disproportionate reduction in the pigment level in the iris. One assumes that something similar is theoretically feasible for hair....

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Tuesday, October 09, 2007

Ethnic Genetic Interests Revisited   posted by DavidB @ 10/09/2007 02:17:00 AM

[Added 10 October: The comments facility on this post has been temporarily suspended due to obscene or offensive comments. Anyone with serious comments can email them to , and I will try to reply to and/or post the comments in due course.]

[Added 14 October: No-one has taken me up on this offer, but my attention has been drawn to a comment elsewhere. See the Note at the end of the post, below the fold.]

In 2005 I commented on Frank Salter's theory of Ethnic Genetic Interests, as set out in his book On Genetic Interests: Family, Ethny and Humanity in an Age of Mass Migration (Frankfurt, Peter Lang, 2003). My post on 'Ethnic Genetic Interests: Part 1' (EPG1) summarised the theory, and stated some basic objections to it. 'Ethnic Genetic Interests: Part 2' (EPG2) covered more technical issues. A post on 'Interracial Marriage: Salter's Fallacy' (IMSF) dealt with a specific topic.

Razib has informed me that Salter's book is available in a new edition (2006) from Transaction Publishers. The main text does not appear to have revised, but the word 'ethny' in the title has been changed to 'ethnicity'.

The new edition also has a short Introduction commenting on reactions to the original edition. These include my own posts. For the small number of people who may be interested in such matters, I have transcribed the relevant passage from the Introduction below the fold, and added a few counter-comments of my own.

In general, I think my posts can still speak for themselves, and I see no reason to make any fundamental change. I will however take the opportunity (below the fold) to correct an oversimplification. I should also say that although I disagree with Salter's conclusions, I recognise the ingenuity and thoroughness with which he has pursued his ideas.

I also take the opportunity now to emphasise something I should have done previously: that differences in gene frequencies between human populations are in general fluid and transitory. Since Salter's aim is to preserve existing differences, this is fatal to his doctrines. Let us consider how such differences arise.

First, they may be due to natural selection still in progress. If an allele is generally advantageous, it will sweep through the world population in a relatively short time. But the process does take some time (of the order of a few hundred generations), depending on the strength of the selective advantage, rates of migration and intermarriage, and so on. Some of the differences between populations are therefore likely to be due to the different stages that selection has reached in different places. Differences of this kind are essentially transitory, and will be eliminated by ongoing selection. The process is unstoppable, unless selective conditions change. All that is needed is a very small amount of gene transfer (introgression) between different populations, and selection will do the rest.

Second, differences in gene frequencies may be due to genetic drift or founder effects in populations isolated from each other. In large populations (e.g. continental races) genetic drift is ineffective unless the alleles concerned are selectively neutral, and very slow even when they are. It is generally assumed (by Salter among others) that many of the genetic differences between human geographical races are of this kind, having arisen when populations were much smaller and more isolated than they are now. If so, then even moderate amounts of migration and intermarriage will narrow and eventually eliminate the existing differences. No feasible amount of 'Salterism' can halt the process, though it may slow it down.

Finally, differences may be due to variation in selective conditions, such as climate, diet, and exposure to infectious diseases. Genetic differences in skin colour, metabolism, blood groups, and the immune system are probably of this kind. Such differences are often clinal and cut across conventional racial groupings, though in some cases (e.g. resistance to malaria) different genes may be responsible in different areas. It is a matter for legitimate concern that increased migration and intermarriage may weaken the adaptedness of populations to their distinctive selective regimes. However, compared to the huge changes that are taking place in selective regimes for other reasons, this seems a very minor concern. Moreover, since differences in selective conditions cut across racial or ethnic boundaries, the resulting differences in gene frequencies are only weakly correlated with Salter's coefficients of 'ethnic kinship'.

I conclude that even if Salter's doctrine of ethnic genetic interests were sound in principle (which it isn't), in practice it would be either unnecessary or futile.

A correction

In EPG1 I commented that:
Salter's doctrine is profoundly anti-eugenic. For Salter, it is in the interest of an individual to preserve and promote the gene frequencies of his own ethnic group, whether the existing gene frequency is good, bad or indifferent, as judged by qualitative criteria. So, for example, it is in the interest of American blacks to promote their own gene frequencies against those of American whites, even if in some respects it would be better for blacks themselves to change those gene frequencies. The doctrine of genetic interests is inherently backward-looking and conservative.

In EPG2 I said:
For Salter, it is by definition adaptive for an individual to maximise the number of copies of his own genetic material, regardless of its selective value. So, for example, it is adaptive for an individual with Huntingdon's [sic: should be 'Huntington's'] Disease to maximise the number of other Huntingdon's sufferers.

Salter's theory implies, for example, that African populations who have migrated to temperate countries should seek to preserve their 'distinctive' African genes - even those, like the genes responsible for sickle-cell anemia, which are actively harmful in their new environment.

In defence of Salter it has been pointed out (though not by Salter himself) that in a few passages he does explicitly allow for the promotion of 'eugenic' genetic change, for example (p.89 of both editions):

Phenotypes can lose inclusive fitness through individual alleles in their genomes becoming maladaptive, due to mutation or to changes in the environment. Those dysfunctional alleles no longer serve the interests of the majority of the genes comprising the genome and thus the individual's genetic interests would be preserved or increased by substitution of maladaptive alleles.[i.e. their replacement by more adaptive alleles].

There are a few other such concessions.

My posts therefore oversimplified Salter's doctrine, and I apologise for the oversight. In mitigation, I would plead that the relevant passages do not occur until nearly 100 pages into the book, they are not given much emphasis, and they are hedged around with qualifications. This is perhaps not surprising. They go against the general tendency of Salter's doctrine, and are difficult to reconcile with his emphasis on the overriding importance of genetic continuity as such. If we accept - as Salter does accept in these few passages - that the maladaptiveness of genes can override the 'ultimate' interest of genetic continuity, where does it end? Pursued to a logical conclusion, the implication of Salter's concessions is that the ultimate test of whether the frequency of a gene should be increased or decreased is its effect on fitness, not its current frequency within the 'ethny'. We would therefore be left with the absurd result that the only genes to which Salter's original doctrine of genetic interests applies are those that are selectively neutral!

I now transcribe the passage from Salter's new Introduction which responds to my original posts:

From the Introduction to the 2006 edition

I [Salter] now turn to two technical points. One commentator has identified a terminological error that needs to be corrected (David B. 2005c [EPG2], point 1). Throughout On Genetic Interests I define an individual's genetic interests as consisting in his or her distinctive genes, some of which are found in kin and fellow ethnics. Such genes exist, but kinship generally consists of shared frequencies of genes, even when the genes concerned are not unique to any one individual. 'Distinctive genes' should be read as 'distinctive gene frequencies' or 'distinctive allele frequencies'. The same commentator thinks that making such a change weakens the emotive force of genetic interests (evidence that even some critics are impressed by it). 'Why anyone should consider this a "vital", "fundamental", or "ultimate" interest is beyond me. Why so much fuss about shifting a gene frequency from, say, 50 percent to 60 percent?' But kinship found within ethnies is homologous with that found within families. Are we to believe that parents do not have a vital, fundamental, or ultimate interest in their children? The point is that Hamilton's theory of inclusive fitness still applies whether genetic interests consist of unique genes or gene frequencies. If any branch of genetics is likely to have emotive force it is surely that which explains the evolutionary and social significance of kinship, whether in family or tribe. The same author [David B.] makes many other criticisms, including some thoughtful philosophical comments, but none are as decisive as that concerning distinctive genes. An example is his criticism of the argument I make in Chapter 8 (section 8.1) that exogamy, marrying outside the ethny, can reduce fitness (David B., 2005a [IMSF]. This is an interesting argument, but one made previously by Grafen, which I discuss on pp.262-5.

Comments on Salter's Comments

"The same commentator thinks that making such a change weakens the emotive force of genetic interests (evidence that even some critics are impressed by it)."

In the cited post I didn't refer to 'the emotive force of genetic interests', so the 'evidence' is purely in Salter's imagination. My objection was to the absurdity of Salter's own emotive rhetoric, when we consider what the pursuit of his 'genetic interests' really involves, namely a minor tweaking of population frequencies for alleles which often have no adaptive significance in any case.

"kinship found within ethnies is homologous with that found within families."

I'm not sure what exactly Salter means by 'homologous', but in fact there are many important differences between the 'kinship' of randomly selected co-ethnics and the ordinary kinship of close relatives. I pointed out some of the differences here. I should however correct or clarify Note 2 to that post. I would now stress that 'relatedness' must always be measured relative to the gene frequencies of a specified population. (This is clearer in Sewall Wright's original correlational concept of relatedness than in the more recent and widely used concept of 'identity by descent'.) The average relatedness between randomly selected members of a population, relative to the gene frequencies of that population, is always zero (apart from sampling error). We therefore should not expect altruistic behaviour to evolve between random members of a population, so far as interactions within that population are concerned.

"Are we to believe that parents do not have a vital, fundamental, or ultimate interest in their children?"

It depends what is meant by 'interest'. Salter's own concept of 'genetic interest' seems to me to be mystical twaddle, so I do not believe that parents have an interest in their children in Salter's sense. Of course, it is undeniable that human individuals do literally care for their offspring. Humans have been selected for an unusual degree of parental care. If they do not have children of their own, they may by default care for their nieces or nephews, or even adopt unrelated children or pets. What I deny is that this specific evolved tendency for parental care derives from, or can be extended to, some general concern for 'genetic interests'. There is nothing to suggest that people usually have any concern for the genetic prospects of their more remote relatives, let alone of random 'coethnics'.

"Hamilton's theory of inclusive fitness still applies whether genetic interests consist of unique genes or gene frequencies."

Salter's frequent references to Hamilton seem to me to be little more than name-dropping. There is no real connection between Hamilton's theory and that of Salter. Hamilton's theory of inclusive fitness applies to the effects of particular genes (alleles). If an allele increases the inclusive fitness of its bearers, then we expect it to increase in frequency in the population until it is fixed. It does not (metaphorically) say to itself, 'Hey, we're up to 60 percent, we can stop now.' In Hamilton's theory an allele has no 'interest' of any kind in maintaining the existing frequency of that allele in the population (unless it is already fixed). Moreover, many of the alleles which differ in frequency between populations are selectively neutral, in which case they do not affect inclusive fitness, and are not covered by Hamilton's theory. Under Salter's theory, in contrast, individuals are exhorted to defend the existing allele frequencies of their own ethnic group, regardless of the selective value of those alleles (apart from the occasional concessions mentioned earlier).

"This is an interesting argument, but one made previously by Grafen."

No, it wasn't. I would be delighted to find myself in agreement with Alan Grafen, who is one of the most brilliant evolutionary theorists currently working, but on consulting the cited work of Grafen I do not find my own argument. The purpose of Grafen's paper [Grafen 1990] is to consider whether organisms have evolved mechanisms for recognizing kin. As a part of this project, he considers the claim (known as Genetic Similarity Theory) that individuals can detect the degree of general genetic similarity of other individuals to themselves. He further considers whether assortative mating is due to such detection of similarity, and whether mating with relatives would be advantageous from the point of view of inclusive fitness. On this last point, he discusses some pros and cons, and sagely concludes: 'Assortative mating in humans therefore seems unlikely to be explained by genetic similarity theory because it probably does not succeed in creating substantial relatedness between mates, it would be an unnecessarily costly way of mating with a relative, and it is dubious whether it is advantageous to mate with a relative anyway'. In reaching this conclusion he appears to accept that mating with relatives would, other things being equal, bring an increase in inclusive fitness, but thinks that this needs to be balanced against other considerations, such as inbreeding depression.

In contrast, my own position is that mating with relatives (in this case, co-ethnics) in itself brings no increase in an individual's inclusive fitness at all, and that it is a fallacy to suppose otherwise. The key point to grasp is that, on neutral assumptions, each inbred mating replaces two outbred matings (one for each partner). I claim no great originality for this point, because (as I mentioned in my post) it is essentially the same as Dawkins's '10th Misunderstanding of Kin Selection', which I discussed here, with a correction here, which is the idea that 'Individuals should tend to inbreed, simply because this brings extra close relatives into the world'. Perhaps Grafen himself has fallen into this fallacy, but it would be more charitable to suppose that his discussion of the issue was simplified for the sake of brevity, as it was peripheral to his main concerns.

As Dawkins recognises, there could be special cases in which inbreeding does increase inclusive fitness. In his discussion of interracial marriage, Salter puts some emphasis on parental care, arguing that this has a greater fitness benefit if offspring are more closely related to their parents, as they would be through inbreeding or breeding within the 'ethny'. This is an intricate point, but my tentative view is that Salter's position is largely but not entirely misconceived.

In all species, there is a trade-off between the number of offspring produced and the amount of resources (including parental care) devoted to each offspring. The general evolutionary principle (usually attributed to David Lack, though he had several precursors) is that for each species there will be an optimum level of parental investment, at which the number of offspring who survive to maturity is maximised (subject to refinements over the timing of reproduction, as expressed in Fisher's 'Malthusian Parameter'). The optimum level is determined primarily by the ecological circumstances and habits of the species. As far as I can see, in general it does not make any difference to the optimum whether the breeding system favours inbreeding or outbreeding (except perhaps through side-effects such as the amount of competition between siblings). The optimum level, as determined by ecology, etc, maximises the reproduction of all the genes of the organism equally, including any genes that promote inbreeding or outbreeding. Such genes are therefore neutral with respect to the optimum level. It may however still be said that a gene for parental care would 'prefer' parental investment to be directed towards inbred offspring, who will on average contain more copies of that gene. I think this is true to the extent that if a parent has both inbred and outbred offspring, its genes for parental care would have an 'interest' in discriminating in favour of the inbred offspring, other things being equal. Of course, this interest would be offset by any reduction in the viability of inbred offspring due to inbreeding depression. In any case, I do not think that this limited preference for inbred offspring, where both inbred and outbred offspring already exist, should be confused with a general tendency to mate with relatives, and thereby to produce inbred offspring. This is an instance of the fallacy pointed out by Dawkins.

I should also stress that even if there is some validity in Salter's comments on parental care, this would not affect my main criticism of his arguments against interracial marriage, which is that interracial marriage does not in general reduce the net 'genetic interests' of the participants, as fallaciously assumed by Salter.

Ref: Grafen 1990: Alan Grafen, 'Do animals really recognize kin?', Animal Behaviour, 1990, 39, 42-54.

Note added on 14 October:

My attention has been drawn to a critique of the above post by J. W. Holliday. I won't give a link, as the critique is personally abusive, but those who are interested will be able to find it easily enough. I recommend it to connoisseurs of paranoid fantasy.

I won't respond in detail. As a famous philosopher once said, comments on comments on comments (etc) are subject to the law of diminishing fleas.

I will however pick up a few points. I emphasised in my post above that differences between populations due to genetic drift will be eroded and eliminated even by modest amounts of migration. Holliday appears to doubt this, but it is a well-established result of population genetics. The strength of genetic drift is inversely related to the size of the population. In a very large population, such as a continental race with a population of hundreds of millions, genetic drift in the population as a whole is extremely slow. Even low rates of migration - say, one in a thousand per generation - would be orders of magnitude more effective in changing gene frequencies. Indeed, subject to certain qualifications, even an exchange of one migrant per generation is sufficient to stop two populations drifting apart. Anything more than this, and the gene frequencies in the populations will tend to converge.

Differences in gene frequencies due to differing selective conditions are another matter. Migration will tend to reduce them, but if selection is strong enough some differences may be maintained. I have never disputed this.

Holliday assumes that I (or rather gnxp, which in his fantasies has a policy on such matters) advocate 'mass migration/miscegenation'. In fact, as I said in EGI1, 'there are sound arguments against large-scale, uncontrolled immigration '. I just don't think Salter's doctrines are 'sound arguments', and I believe it would be positively harmful to the case for immigration control if it became tainted with Salterism. As for 'miscegenation', I gave my considered views on the effects of interracial marriage here. In my 'Salter' post on the subject (IMSF) I was simply concerned to show that Salter's main argument against interracial marriage is a fallacy. Holliday concedes that it is a fallacy, but imagines that he can get Salter off the hook by pointing out that my assumption of 'neutrality' is unlikely to be strictly true in practice. Well, of course. It is an idealisation which simplifies the arithmetic for purposes of presentation. But Salter's own approach remains fallacious even if we relax the assumption.

Holliday rejects my conclusion that "the implication of Salter's concessions is that the ultimate test of whether the frequency of a gene should be increased or decreased is its effect on fitness, not its current frequency within the 'ethny'." But Holliday's counter-argument is vague and unquantified. In Salter's system, an individual's EGIs are measured by multiplying the number of his 'co-ethnics' (other than close kin) by the relevant degree of ethnic 'kinship'. Any gene substitution which increases the fitness of the co-ethnics will therefore increase the individual's EGIs unless by making the substitution the degree of 'kinship' is reduced by a larger factor. This is extremely unlikely to be the case, since ethnic kinship is averaged over a large number of different genes (probably thousands). The effect of any single gene substitution on the degree of kinship would therefore be very small, and would be outweighed by even a modest fitness advantage (of the order of one in a thousand).

It should also be noted that if we replace 'distinctive' genes, i.e. those with different gene frequencies between two populations, by genes that have equal frequencies in the two populations, then the negative kinship between the populations will also be reduced. I have pointed out previously that for consistency we should always count negative as well as positive EGIs, in which case the net effect of a gene substitution on EGIs is zero (assuming equal population sizes), and any fitness benefit of the substitution is pure gain.

But as EGIs are nonsense anyway, I think this is like arguing about whether chimaeras bombinate in the void.

Finally, Holliday stresses that Salter recognises the inevitability of genetic change and evolution even if his policy recommendations (essentially, preventing migration and intermarriage) were implemented. I agree that it is possible to find passages of this kind in his book. The fact remains that the overwhelming emphasis of his doctrine is on defending existing genes and gene frequencies as they are, and he does not (in my opinion) explain why some changes are to be cheerfully accepted while others are to be fought tooth and nail. If an author were to write a book making a passionate plea for freedom of speech as an 'ultimate' and 'overriding' value, but inserting sporadic unexplained concessions such as 'except for libel', 'except for obscenity', 'except for religious abuse', and so on, we would not form a high opinion of his or her consistency and intellectual rigour.


Friday, October 05, 2007

Racial DNA Profiling?   posted by Razib @ 10/05/2007 01:13:00 PM

Wired has an article up titled The Inconvenient Science of Racial DNA Profiling. The core of the story is Tony Frudakis, who has written papers such as Eye colour: portals into pigmentation genes and ancestry. The science is pretty easy to understand. You don't need that many genes to fix in on someone's likely racial identity. Take two genes, SLC24A5 and DARC. There are genetic variants in African Americans on these loci which are basically non-existent in those of European descent. Because African Americans are genetically admixed with about 20% of their ancestry being European they have a less unequivocal profile on these loci; but all you need to do is increase the number of genes to increase your confidence that you've made a positive identification.

The science is banal. The politics, less so. For example:

Besides the expense, many people who might benefit from DNAWitness either don't know it exists or are extremely skeptical that it works. William C. Thompson, Chair of the Department of Criminology, Law & Society at UC Irvine is a prominent expert on the use of DNA in criminal trials but was only marginally familiar with this technology. When I tried to describe how it works, he literally screamed at me, calling Frudakis a hack and a charlatan who obviously did not understand statistics.
But even the people one might think should be his biggest allies aren't supporting that, including Tony Clayton, the special prosecutor who tried one of the Baton Rouge murder cases. Clayton, who is black, admits that he initially dismissed Frudakis as some white guy trying to substantiate his racist views. He no longer believes that and says "had it not been for Frudakis, we would still be looking for the white guy in the white pick-up truck." But then he adds, "We've been taught that we're all the same, that we bleed the same blood. If you subscribe to the (Frudakis) theory, you're saying we are inherently unequal."

William C. Thompson has written about forensic DNA evidence in his research, so his anger must not have been driven by ignorance. And as for the idea that because two populations have different genetic profiles that means that they are "inherently unequal," that's depends on what metric you're using as a measure. A lawyer should know that all Americans have the same rights and equal worth before the law whether they are good at digesting lactose or tall, both by the grace of genes.

But think about what Frudakis is doing, he's taking genes and mapping them onto phenotypes. For example, if someone has a particular allele of OCA2 there is a strong conditional probability that they will, or won't, have blue eyes. Amazing! It changes everything! Who knew that blue eyes were genetic! Now we're all unequal...or are we? The fact is that everyone knows that skin color, hair form, eye color and a host of other traits are due to your inheritance, your genes. It just goes to show how magical most people view science in that they are terrified that now we know the genes which are responsible for the variation which we intuitively would assume was due to inheritance of different genetic variants in the first place. This goes to some extent to confirm A.W.F. Edwards' criticism of Lewontin's Fallacy, if we derive our normative prescriptions from science's understanding of nature our basis is fundamentally shaky because science does not deal in ultimate truths. Lewontin's obscurantism convinced everyone that genetic differences were trivial, even though they all noted the distinctive physical types which obviously derive from genetic differences. Now that genetics, or specifically genomics, is advanced enough to fill in the gaps and elucidate the genetic architecture underpinning distinctive physical types people are terrified because they rested in their presuppositions on Lewontin's Fallacy.

Finally, there is the issue of the practical use of these tests. As noted in the article genomic profiles aren't necessarily cheap, and they aren't necessarily value added in some cases when cost is taken into account. But, if we are likely going to see the era of the $1,000 genome within the next 15 years, how expensive do you think a kit which checks a few dozen markers will be? For most people science is magical, but when the wizardry becomes a banal part of the consumer life through technology people accept it as a having real truth value. All the expositions of genetic correlation structure are going to do far less in debunking Lewontin's Fallacy than the coming ubiquity of personal genomics.


Thursday, September 27, 2007

Cosma on IQ & heritability   posted by Razib @ 9/27/2007 09:20:00 PM

Cosma Shalizi has put up a gigantic post on IQ & heritability; he originally titled it "Duet for Leo and Razib," implying that I, and the audience here @ Gene Expression, are the targets of his eloquence (at least in part). Now, I have to admit something, I'm not really interested in psychometrics that much anymore. It has been a while since I have been, stupid people are obviously stupid and I am not interesting in debating that fact. I take my own opinions in this area as background assumptions, so I'm not going to respond to Cosma. In fact, I won't read the post right now, there's some interesting stuff on HLA & heterozygosity that I want to check out! But, I do invite readers to digest what Cosma is saying, because I guarantee you that you'll see it replicated by lesser minds elsewhere.

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Wednesday, September 26, 2007

The biodiversity of human feet   posted by Razib @ 9/26/2007 07:43:00 PM

Native Americans get custom sneaker:
Nike researchers and developers spent two years designing the shoe, traveling to seven locations to look at the feet of 224 Native Americans from 70 different tribes. They created a shoe to fit the average Native American foot, which is wider than the foot the Nike Air Pegasus running shoe is designed to fit. About 164 members of the Confederated Tribes of Warm Springs tested prototypes of the shoe before its release, the company said.

Jeff Piscotta, senior researcher in Nike's Shoe Research Laboratory, said company researchers have developed a similar custom-fit shoe design for Japanese runners, and as part of the run-up to the 2008 Olympics are researching the feet of Chinese athletes and runners to produce a better-fitting product.

This is fascinating. The reason these shoes were developed was to encourage physical activity, something that comes more naturally when your feet aren't aching. Assman has noted before that South Asians might be more flexible than the typical human, which likely results in flatter feet, so this foot's-eye viewpoint might be pretty practical in tailoring shoes toward populations.


Thursday, September 20, 2007

Buddy, can you spare an SNP?   posted by Razib @ 9/20/2007 07:50:00 PM

New paper out in PLOS Genetics, PCA-Correlated SNPs for Structure Identification in Worldwide Human Populations:
Genetic markers can be used to infer population structure, a task that remains a central challenge in many areas of genetics such as population genetics, and the search for susceptibility genes for common disorders. In such settings, it is often desirable to reduce the number of markers needed for structure identification. Existing methods to identify structure informative markers demand prior knowledge of the membership of the studied individuals to predefined populations. In this paper, based on the properties of a powerful dimensionality reduction technique (Principal Components Analysis), we develop a novel algorithm that does not depend on any prior assumptions and can be used to identify a small set of structure informative markers. Our method is very fast even when applied to datasets of hundreds of individuals and millions of markers. We evaluate this method on a large dataset of 11 populations from around the world, as well as data from the HapMap project. We show that, in most cases, we can achieve 99% genotyping savings while at the same time recovering the structure of the studied populations. Finally, we show that our algorithm can also be successfully applied for the identification of structure informative markers when studying populations of complex ancestry.

The text has the nitty-gritty for now many SNPs are needed for them to generate the population clusters. They seem to be selling the method on a "faster, cheaper" spin. Jump to the discussion though and something interesting does pop out that doesn't require mediation upon the uses of orthonormal vectors:

Our findings demonstrate that to a large extent, SNPs identified as structure informative in one geographic region are not portable for the analysis of populations in a different geographic region, suggesting that the forces that shaped population structure in each geographic region have influenced different parts of the genome. However, analyzing jointly nine populations from around the world and 9,160 SNPs, we showed that using 50 PCA-correlated SNPs we can assign the studied individuals with 100% accuracy to their population of origin....

What could those forces be? You can connect the dots.

Finally, a small detail which I thought was interesting:
...As we have shown here, analyzing two independent Puerto Rican datasets, PCA-correlated SNPs can be successfully used to reproduce the structure of admixed populations and predict the ancestry proportions of the studied individuals. Interestingly, we found that interindividual variation across the Native American axis in the Puerto Rican samples that we studied was very low, perhaps depicting the fact that admixture with Native Americans occurred very long ago, and was random over several generations.

This seems to make sense, the Taino were absorbed into the Puerto Rican population in the 16th century. Subsequent to this there were hundreds of years of African and European immigration to the island. Nevertheless, a substantial proportion of the mtDNA lineages in Puerto Rican are Amerindian, which implies that the Europeans and Africans were disproportionately male (otherwise European and African mtDNA lineages would have slowly replaced the Amerindian ones over time).

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Friday, September 07, 2007

The new races of man....   posted by Razib @ 9/07/2007 02:33:00 PM

Over 40 years ago the physical anthropologist C.S. Coon wrote The Origin of Races. Along with The Living Races of Man this book is an excellent source for on all sorts of obscure and hard to find anthropometric data. As Peter Frost has noted it can be rather difficult to find information on the distribution of the most mundane of human characteristics because of the shift away from the descriptive physical anthropology. If you want frequencies on blue eyes in Sweden, your data set is likely to predate World War II.

That being said, the model posited in The Origin of Races is false, Coon hypothesized that six primary races had their origins in independent transitions to sapiency by their hominid precursors. In this model the seeds for racial difference existed on the order of tens of millions of years before the present. Though a great collector of data and a vivid storyteller, like most of the physical anthropologists of the first half of the 20th century Coon's scientific methodology was heavily intuitive and seemed to be guided mostly by gestalt impression.

The subsequent genetic revolution, starting with the successful challenge by the proponents of the molecular clock to the older paleontological model of the origin of hominids which assumed a very early separation from the great apes, and ending with the ascendance of Out-of-Africa over a Multiregional conception of modern human origins, made the older anthropological taxonomy look amateurish. L.L. Cavalli-Sforza's The History and Geography of Human Genes rendered much of the more imaginative anthropological literature on racial history a historical footnote. I've avoided terms like Mongoloid and Caucasoid because of their associations with an older anthropological taxonomical tradition which seemed basically irrelevant in terms of the theoretical framework. Even the early serological work on the Ainu of Japan seemed to show that this putatively Caucasoid population, as determined by older anthropometric methods and description, was more closely related by descent to the populations of East Asia than to Western Eurasians. Analysis of the Indian subcontinent seemed to show that there was more genetic distance between these peoples and those of the Middle East & Europe than some of the older models had projected. I did not see great need to look to the older literature for pointers or guides when genetic markers could tell the full tale.

But lately I've been reconsidering. Though the racial migrations posited by the physical anthropologists of the early 20th century were generally more shaped by their cultural context and imagination than reality, the anthropometric data they collected wasn't manufactured out of whole cloth. The description tracked a real pattern in the data. Though the hypotheses were not very informed by the latest in evolutionary and genetic theory, they were not uninformed by fact. Lately I've been posting a lot about lactase persistence and skin color. These two genetic characteristics have come a long way in terms of their understanding over the past few years. At my other blog I posted yesterday about a study which studied the skin color variation in South Asians. The SNP of SLC24A5 which is fixed in Europeans and not present in Africans and East Asians, seems to exhibit high penetration within South Asia. In fact, it explains about the same proportion of the skin color difference between the lightest and darkest quintile of South Asians as it does in relation to the complexions of Europeans and Africans. Lactase persistence also exhibits a similar pattern, the same allele seems to have swept from the Atlantic to the Bay of Bengal. Its penetration into Sub-Saharan Africa is patchier, and it seems not to have any discernible impact on East Asia.

In The Real Eve, a survey of the literature on neutral genetic markers as proxies for ancestry, Steve Oppenheimer asserted that the basic population groups we see around us today were established and in place by the end of the last Ice Age. In other words, most of the ancestors of people in East Asia, the Middle East, South Asia, Europe and Africa were on those continents 10,000 years ago. Of course there have been changes within the continents, the expansion of the Han within the last 3,000 years in China or the Bantu expansion in Africa are two examples. Additionally, there have been genetic overlays upon the bedrock, for example, the injection of African and Arabian female and male lineages respectively throughout what has become the Arab world over the last 1,500 years. The signature of a Neolithic demic diffusion into Europe from the eastern shores of the Mediterranean starting about 10,000 years ago. Evidence in South Asia of population movements from West and Central Asia from antiquity down to the Islamic period. Nevertheless, in narrative generated by the neutral markers is that the races of man were extant more or less 10,000 years ago and only the margins and details have been affected by subsequent migrations.

I think this is wrong, and Oppenheimer in his chapter on East Asia supplies a clue to why this story isn't complete: he notes that the classical East Asian physical type, that is, Mongoloid, seems to emerge very recently. One could posit that this and artifact due to the paucity of fossil remains in this region for anatomically modern humans. But no, I think the answer is that the Mongoloid physical type emerged within the last 10,000 years due to recent human evolution! We also know from the data that the classical Northern European with fair hair, blue eyes and a taste for milk is also a recent evolutionary development, within the last 10,000 years. In Africa malaria probably resulted in some of the highest selection coefficients known to man, all within the last 5,000 years. In South Asia we know that lactase persistence and lighter skin are due to recent evolution, and likely both are exogenous. In fact, the allele is identitical by descent with that which is common in the Middle East and Europe.

And this last fact brings me to another observation: the patterns of cultural diffusion which seem to characterize the pre-modern world might very well serve as a map for the sweeping of mutants of large effect across Eurasia over the past 10,000 years. The genetic architecture for light skin color are radically different in East Asia as opposed to Europe, the Middle East and South Asia. Similarly, the alleles for lactase persistence that are West Eurasian are found in the same broad swath of land where SLC24A5 seems to have made an impact: from Europe down into North Africa across the Middle East and South Asia. This area is also the classical home of the Caucasoid race, which Coon characterized by its lack of specialized features vis-a-vis Africans and Mongoloids. I am struck by the correspondence here with a particular cultural pattern that reoccurs: memes which originate along the fringe of Eurasia east from India and west to Spain as well as at the nexus with Africa seem to stop at the Sahara and the Himalaya. Consider the scripts dominant from India to Spain, they derive from Aramaic. In contrast, Chinese writing is based on a different model. Consider the Indo-European and Afro-Asiatic languages which span such broad expanses, from the Atlantic to the Bay of Bengal, from the Niger river to borders of Anatolia. Consider that the One True God is worshipped from Europe to Bengal.

In The Human Web the historian William H. McNeil describes the slowly growing networks of information which spread across the globe over the past 3,000 years. He posits the origination of hearths, proto-civilizations, which slowly became entangled in a dense network of trade and political unification. One of the earliest major dynamics which persisted to the relatively recent past was the separation of East Asia from Western Eurasia. Though there were contacts and diffusions, the three major cultural hearths, the West (Europe & the Middle East inclusive), India and China did not have symmetrical relationships. The West and India, though alien and viewing each other as exotics, did have a non-trivial amount of trade and cultural exchange. As early as the Persian Wars soldiers recruited in the Indian provinces could be found involved in European conflicts, while Indian philosophy seems to have had an indirect and diffuse influence upon later Greek philosophy (by which I mean Neo-Platonism and such). Small communities of Christians & Jews and Roman coins in southern India, or the adventuring of Central Asians and Africans in armies of Muslim sultans, attest to South Asia's connections to the West. Even as far back as the Sumerians there was most certainly contact between India and the Middle East (references to Meluhha and trade items found in Harrapa is evidence of this). In contrast, ancient China was a relatively isolated land encircled by barbarians. Granted, some cultural ideas seem to have percolated from the West to the East, and the presence of Christians, Jews and Muslims in China from an early period attest to the more vigorous contact of the last 2,000 years. Nevertheless, the extinction of both the early Jewish and Christian communities attests to the relative isolation from the wider world which still characterized China until the early modern Age of Exploration.

And so it might be with genes. Though there was certainly some traffic between the antipodes of Eurasia, the migration was low enough that independent mutations with similar phenotypic effects seem to have arisen in the different domains. With the rise of agricultural society, enormous populations, increased rate of cultural evolution, I suspect that biological evolution was also cranked up through the simple change of prosaic population genetic parameters (more mutants, more long distance migration, etc.). Alleles of large effect could have swept repeatedly across distinct and long separate populations and bound them together as functional clusters. At the end of the last Ice Age the whole region from the Atlantic to South Asia was characterized by a sparse population just reemerging from their refugia. Long isolated from each other by the Last Glacial Maximum these populations were genetically quite distinct, especially between South Asia and Europe & the Middle East. But just as the rise of long distance trade spread ideas across these disparate zones, so genetic evolution swept along the routes of migration. A group like the Indo-Europeans may be only a small proportion of the ancestry of modern Persians, Indians, Germans and Russians, but they might have been significant in spreading genes of great impact across this broad zone, generating surface commonalities which contradict the deep time cleavages wrought by the isolation of the Ice Age. What I am positing is an inversion of the dynamic which Henry Harpending brought to my attention years ago, he pointed out that some populations exhibit similarity of ancestry but sharp differences of phenotype. Harpending's model was that social selection on particular loci could perpetuate physical differences between groups which intermarried and so equilibrated on most markers. In contrast, the model here that I am proposing is that the differences of ancestry may belie the common ground on major functional loci across several population clusters. And similarly, adaptive evolution may result in divergences in appearance between groups with relatively recent common ancestry, as seems the case in relation to Ainus and other East Asians. All in all, it is a complex & baroque picture, but one which I believe will exhibit interesting systematic patterns. Presenting this in a pithy, precise and accurate manner to the public, well, that's a different story....

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Friday, August 31, 2007

10 Questions for Greg Clark   posted by Herrick @ 8/31/2007 02:04:00 PM

In his new book A Farewell to Alms, Greg Clark, an economic historian at the University of California, Davis, contends that "[t]he New World after the Neolithic Revolution offered economic success to a different kind of agent than had been typical in hunter-gatherer society: Those with patience, who could wait to enjoy greater consumption in the future. Those who liked to work long hours. And those who could perform formal calculations in a world of many types of inputs and outputs...."

Clark also provides archival evidence that in medieval Britain (and to a lesser extent in China and Japan) the wealthy-who presumably had those "middle class" skills in abundance-raised more children than the average person. If you put these pieces together-a system that rewards a new set of abilities, plus greater reproductive success for those who have those abilities-then all you need to get some form of selection is one more link: A transmission mechanism. On the nature of the mechanism, Clark leaves the door wide open. Could be parent-to-child cultural transmission, could be genes, could be both.

While much of the discussion of Clark's book has focused on his "survival of the richest" hypothesis, Clark himself appears to be equally devoted to demolishing the widely-held view that economic institutions are the key to modern economic growth. He notes that the British people had solid property rights, limited government, and sound currency for centuries before they had their Industrial Revolution. Drawing on early work by Nobel Prize-winner Douglass North, he argues that economic institutions are largely endogenous and relatively efficient, at least when we're talking about time horizons lasting a century or more. If institutional change wasn't the driving force behind modern economic growth, then what was? In Clark's view, the driving force was change within human beings themselves.

1. In some early work, you wondered why workers in British cotton mills were so much more productive than workers in Indian cotton mills. You discuss this in the last chapter of A Farewell to Alms. You looked at a lot of the usual explanations-incentives, management, quality of the machines-and none of them really seemed to explain the big gap in productivity. Finally, you seemed to turn to the idea that it's differences between the British and Indian workers themselves-maybe their culture, maybe their genes-that explained the difference. How did you come to that conclusion?

Clark: I came to economics as an undergraduate expecting, as is the central view of economics, that the explanation for wealth and poverty would ultimately be located in social institutions and that people everywhere have basically the same aspirations and abilities.

But unlike most of my colleagues in economics I have always been interested in the mechanisms, and the fine details, of how things actually function. Much of modern economics is entirely theoretical, and even most empirical work in economics involves just looking at very high level correlations between variables such as income per person and education, or democracy, or the openness of trade.

When I set out in my PhD thesis to try and explain differences in income internationally in 1910 I found that asking simple questions like "Why could Indian textile mills not make much profit even though they were in a free trade association with England which had wages five times as high?" led to completely unexpected conclusions. You could show that the standard institutional explanation made no sense when you assembled detailed evidence from trade journals, factory reports, and the accounts of observers. Instead it was the puzzling behavior of the workers inside the factories that was the key.

2. Your book is clearly a call for a new research agenda in the fields of economic growth and economic history, one focusing less on institutions and more on what we might broadly call "labor quality." But your key hypotheses seem to turn on the question of how and why entire workforces change across the centuries, and involve questions of culture, child-rearing methods, and perhaps human genetics-fields quite outside the expertise of most economists. If you could command an army of, say, biologists, anthropologists, and neuroscientists to test your hypotheses about long-term changes in labor quality, what would you have them work on?

Clark: That is a great question. If, as is possible, the pre-industrial era changed people genetically to be better adapted to market economies, then a systematic comparison of the DNA of societies should find correlations between gene frequencies and the histories of these societies. If genetic change was also occurring in historical time, as opposed to the pre-historic era, then we would expect these changes to be incomplete even in societies with a long history of settled agriculture. In that case we would actually predict class differences genetically! The rich in these societies would differ genetically from the poor in certain systematic ways! All this should be testable at some point.

If the change was purely cultural, then we still might be able to discover systematic behavioral differences between poor and rich in modern capitalist society, such as over time preference rates, that correlate with differences between rich and poor societies.

3. What do you think are the weakest links in the now-conventional "Institutions Matter" chain of reasoning?

Clark: The book challenges the modern orthodoxy of economics - that people are essentially the same everywhere, and with the right set of institutions, growth is inevitable - in three ways. First by showing that there were societies like medieval England where the institutional structure provided every incentive for growth, yet there was no growth. Second by pointing out that by objective measures the institutions of many highly successful modern economies, such as in Scandinavia, provide much poorer incentives to individuals than those of very poor economies. And lastly by showing that in the long run economic institutions that would prevent growth tend to get replaced endogenously by ones that are pro-growth.

4. You provide a variety of evidence that interest rates have fallen over the centuries; this is a fascinating set of data that we've discussed before at Gene Expression. Should economic historians still be searching for transaction cost stories to explain this fall in interest rates-e.g., lenders needed a high return in ancient Rome to compensate them for the high cost of searching for safe borrowers-or is that search likely to hit a dead end?

Clark: Interest rates on safe assets like houses and land fell from 25% or more in Ancient Babylon, to 10% in Ancient Greece, Roman Egypt and medieval Western Europe, to 4% in the eighteenth century in the Netherlands and England. Most economic historians assume this just represents transaction costs. But I can show in cases such as medieval England that transaction costs have nothing to do with this - the real return on investments as safe as modern Treasury Bonds was 10% or more. So I am confident that something much more fundamental was changing over these years.

5. You use data on British wills to argue that the British people of today are by and large the descendants not of peasants and not of the violent medieval aristocracy-both groups failed to reproduce themselves. Instead, the British people of today are largely the descendants of the bourgeoisie of the middle ages. Nowadays, that seems to be a testable hypothesis; have you run into genetic evidence bearing on what you call the "survival of the richest?"

Clark: I agree that, in principle, this is a completely testable hypothesis. If there was genetic change in the Malthusian era then we will find systematic differences in genes that influence behavior such as patience and propensity to violence between groups such as the British and those such as Australian Aboriginals that had no experience with settled agriculture.

However, as far as I am aware, the identification of genes that influence such behaviors is at a very early and tentative stage. The only such studies I have seen reported are those of differences across ethnic groups in variants of genes encoding monoamine oxidase enzymes.

6. How are economists reacting to the book? In particular, are there any misunderstandings that you'd like to address?

Clark: I expected a hostile and perhaps even dismissive reaction, given the controversy that the "survival of the richest" argument was bound to create, and given the attack on the modern orthodoxy amongst economists about institutions being the key to wealth and poverty. But economists who have read the book, even when they remain skeptical of the conclusions, have generally found it interesting and challenging. They have been surprised to learn in particular that the history of economies is not anything like the implicit assumptions they have, based on modern economic doctrine.

7. One implication of your model is that human populations that haven't been through the full Neolithic Revolution are going to fail miserably when they try to build a modern market-oriented society. If people turn out to as hard to change as they appear to be-if neither culture nor genes prove to be all that malleable in the medium-run-then how would you recommend improving the lives of these people? Do you think economists can design institutions that can help make these populations productive?

Clark: Anyone who reads history cannot fail to be impressed by the difficulties that hunter-gatherers, or societies with only limited experience of settled agriculture, have in successfully incorporating into the modern capitalist economy. I spent a week in Australia this summer, and the plight of Australian Aboriginals is very sad. The surviving Aboriginal communities have seen tremendous rates of poverty, alcoholism, drug use, violence and sexual assaults.

But an important point in the book is that while some of this cultural variation may be due to the long histories of societies, there is a lot of cultural variation within these constraints that produces dramatic differences in wealth in modern societies. So there is no ground for fatalism on the possibilities for any society. The problem is that measures to reform the cultures of societies seem difficult to devise. Look at the lack of success the Chinese Communist Party had in remaking Chinese Culture. China has emerged from a period of extreme ideological indoctrination seemingly with its pre-communist love of individual wealth and status completely intact.

8. You emphasize that "[t]he argument is not that agrarian life was making people smarter." But you also emphasize that agrarian life placed greater value on verbal and mathematical skills than hunter-gatherer life. Let's set aside for the moment the question of whether these skill changes were cultural, environmental, or genetic. Are you claiming that the rise in math and verbal skills was counterbalanced by an equal loss of some similarly valuable hunter-gatherer mental skills? In other words, were the mental effects of the Malthusian process zero-sum? If so, what process within your model would make that occur?

Clark: I wanted to emphasize in the book that I was not advocating any kind of Social Darwinism. The long Malthusian economy that preceded the Industrial Revolution changed people, but there is no evidence it made them "better" or "smarter." Indeed there is evidence that we did not become any happier as result of economic growth.

Anthropological accounts of forager societies suggest that people in these communities have strikingly developed powers of observation and memory (as well as an amazing ability to endure pain) - they are just not abilities that the modern market economy places much value upon.

9. Bowles, Camerer, and an interdisciplinary research team led a series of ultimatum-game studies in pre-modern societies; the found incredibly diverse outcomes. By contrast, across modern societies, ultimatum game play is much more similar, so it looks like the modern world really is a world of conformity, at least on this topic. How do you think their experimental evidence bears on your question of whether the "long Malthusian night," as you call it, selected for a certain set of behaviors and attitudes?

Clark: I have seen these results reported, but had not thought of relating them to the arguments of the book. I would have expected that pre-modern societies would have had a common response, but potentially a different response than in modern societies. So I do not think I could call this any kind of vindication of the hypothesis in the book.

10. What's the next project?

Clark: I always have several going at the same time. One is a follow up to the "survival of the richest" study for England reported in the book which will look more closely at the intergenerational transmission of economic success with a much larger set of data, and seek to show through examination of the effects of family size that the mechanism is indeed almost entirely the transmission of culture or genes. This study will also look over the whole period 1600-1914 and examine when and why richer men ceased to have more children than average and began to have less. I would love to use this data to try to tease out whether we have just cultural evolution as opposed to genetic - I just cannot think of any way to do that!

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Tuesday, July 10, 2007

The demographics of top law professors   posted by Razib @ 7/10/2007 04:08:00 PM

Via a reader I found a Imbler Volokh post on the demographics of top yong law professors. You can see his spreadsheet here. Volokh says:
If you thought the sex picture was hard to explain, try this: If you look at the same top 50 most-cited who entered law teaching since 1992, you also see that (by my rough count, and judging by likely ethnicity, not by religiosity) 19 are Jews [38%], a group that makes up 2% of the full-time working population. Part of this is the wild overrepresentation of Jews generally among the legal professoriate, a number that itself is hard to explain - Jim Lindgren's tentative survey from several years ago reported that 26% of law professors at top 100 law schools were Jews - but the numbers exceed even that.

Another 12 are Asians (meaning East or South Asians), a group that makes up 4% of the full-time working population. If you separate out South Asians (since in many ways it's just zany to lump Indians together with Chinese, or for that matter to lump together Chinese, Koreans, and Japanese), you'll find that 5 of the top 50 are South Asians, though South Asians make up 2/3 of 1% of the population. I don't recall precisely what fraction of the legal academy is Asian, but my recollection is that the fraction is no more than 5%, and thus far less than the 24% (or 10% for South Asians).

I generally track data about the medical and the scientific profession because I have friends in these fields (e.g., around 1 out of 20 to 1 out of 10 medical students in the USA currently is probably of South Asian ancestry). I didn't know much about law, it seems a field where cultural fluency matters much more than in medicine or the natural sciences, so I assumed that persons of Asian ancestry wouldn't be well represented.


Saturday, July 07, 2007

Jewish Genius, the follow up   posted by Razib @ 7/07/2007 03:37:00 PM

As most of you know Commentary has a series of letters & a response from Charles Murray following up his article titled "Jewish Genius." Most of the letters aren't particularly intelligent or sincere. Their general form is to dispute the possibility of intergroup differences and throw out all sorts of red-herring objections or insinuations of bad faith or ignorance, or alternatively to simply not understand evolutionary biology with any degree of depth so as not to be manifestly moronic. God knows how idiotic most of the letters must have been if these are the "good" ones. Greg & Henry have a response up to Charles' original article, and predictably I tend to agree with the basic outline. But, I feel I have to reiterate a point I made earlier in response to the original piece. Charles states:
As for the New Testament, unless one wants to argue that Jesus was not the source of his own teachings, and that Paul did not really play the role in formulating Christian theology that he appears to play, I do not see how one avoids concluding that the foundation of the New Testament's spiritual and intellectual power is Jewish.

The spiritual power is irrelevant to me, am I willing to grant that if there is a distinction to be made between pagan and Hebraic religiosity than the Christian religion has at its core a particular Hebraic sensibility. But I want to focus on the intellectual power, since that is the point of Charles' original article: systematic theology grounded in Greek philosophical traditions and methods was a Hellenic enterprise, not a Hebrew one. I say Hellenic specifically because the early Church theologians were generally culturally part of the Greek speaking intelligensia of the Roman Empire, not the Latinate administrative and legal class, let alone the Jewish minority. I've read the New Testament and broadly speaking there are theological elements to it, and certainly those were often exposited by Jews (whether the theology is fundamentally pagan or Hebraic in origin is irrelevant to me since Charles' contention is that Jewish intellectual brilliance is reflected in early Christian theology). But the shining intellectuals of the early Church tended to gentiles. For example, the Doctors of the Church are an eminent list recognized by the Roman Catholic Church. While the Latin intellectuals, such as Augustine or Ambrose, were eclectic and concrete in their thinking and intents, the Greeks such as Gregory of Nazianzus were more abstract and focused on the science of theology.

Myself, I don't find theology particularly interesting or insightful, but, I can't deny that a lot of intellectual firepower went into it and absorbing theological treatises require a level of close reading and attention which one does not associate with perusals of the Letters of Paul. If Charles means by theology the ideas exposited in the New Testament itself, I can grant that it is a very Jewish body of work in authorship (though not overwhelming). But I can not agree that the New Testament's theology is of high intellectual caliber, rather, its basic ideas are relatively accessible to all believers and the language is geared toward the modal intelligence (even the rhetorically elevated Gospel of John is intelligible to people of normal intelligence). If by theology one means the body of work which drew from Greek philosophical traditions, then I can grant that there is some intellectual heft and luminosity on display, but I can not grant that the authors are Jewish because we know the life backgrounds of many of the brightest lights and they were from gentile backgrounds, with a fair number converts from paganism (e.g., Augustine). As one would expect a priori from the division of labor during the Roman Imperial period, among the Christians the Greeks tended to focus on the more abstruse philosophical domains while the Latins were more worldly. This is all established history, so I can not see the point of controversy. Of course Charles can allude to the fact that the foundation of the systematic theology elaborated by the gentile intellectuals was Jewish. So what? Algebra and "Arabic" numerals were introduced into Europe from the Islamic Middle East, but we wouldn't discount the achievements of Europeans in abstract mathematics because the foundation of their abstractions was exogenous.


Wednesday, February 14, 2007

Human biodiversity @ SI   posted by Razib @ 2/14/2007 09:23:00 PM

Readers interested in the range of human phenotypic variation will be interested in inspecting the new SI model index. In particular, some readers might find the Brazil models gallery of particular interest. A certain GNXP contributor will appreciate this photo.

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Friday, August 19, 2005

Blonde Australian Aboriginals   posted by Razib @ 8/19/2005 07:56:00 PM

It's really frustrating when you can't find information via google, but, it just reminds you how shallow the the data mining of search engine crawlers can be. On this weblog people have mentioned blondeness among Australian Aboriginals multiple times, and ultimately we really haven't gotten anywhere (no one has brought up novel data) because no one has any information to offer aside from what they read in C.S. Coon's books when they were younger. There isn't much out there on the web.

Luckily, I decided to check the local college library, and I found Joseph Birdsell's Microevolutionary Patterns in Aboriginal Australia, which has a large section addressing the issue of blondeness among the indigenous people of the antipodal continent. Below, I will summarize most of Birdsell's data and analysis so that google will at least have this to crawl now.

But first, I want to address a minor point that often comes up. One hypothesis about Australian Aboriginal blondeness is that it is due to admixture with Europeans, in particular Dutch sailors who entered into undocumented liasons with native women prior to British colonization. This to me seems like a ludicrous assertion for the following reason: if the blonde alleles introgressed from another population, they can be thought of as proxies for the ancestral admixture of Western Europeans into these tribes. Though a very high frequency of tribal members exhibit preadult blondeness, there are almost no other European diagnostic phenotypes in evidence! That is, their skins are rather dark and their features classically Australian Aboriginal. Most people talk about European blondeness as if it is a recessive trait. I have issues with that simple idea, but, taking it at face value the frequency of blonde alleles in a panmictic population should be higher than the frequency of the blonde phenotype,1 so we are talking about a rather high level of admixture if the blondeness is due to European ancestry. On the other hand, there are no other visible signs of this ancestry. One could hypothesize of course that the initially low frequency (attained via admixture) spread through the population because of positive directional selection on the trait. So in that case the alleles are of European origin, but the frequency of blondeness is not diagnostic of ancestry because it is not a neutral trait. But Birdsell's data points away from a European origin for blondeness, and many of the recollections of readers of GNXP are correct as to the character of this trait among Australian Aboriginals.

To review, there are two primary melanin pigments, dark eumelanin and red-gold pheomelanin. The dosage of these two pigments results in the various hair colors we see in people. Redheads tend to have a great amount of pheomelanin, but almost no eumelanin. Ash blonde people are the reverse when it comes to pheomelanin, while golden blonde individuals tend to be somewhere in the middle. People with auburn hair have relatively high levels of both. But note that pheomelanin is more diffuse and less abundant, and it is no a surprise that black haired individuals may simply mask their "red" pigment. Many people with black hair (including yours truly) go through a "red blonde" phase during hair bleaching, as the dense eumelanin granules are stripped away by the bleaching agents first. It seems that the expression of the phenotype is dependent on many genes, though a few, like MC1R, have an outsized influence (perhaps through regulation of other loci). This is probably one reason that despite the typological division of Europeans into "blondes," "brunettes" and "redheads," there tends to be a continuous gradation of color. Not only do the combinations of eumelanin and pheomelanin dosage add "mixed" categories (strawberry blonde, auburn) to the triplet, the expression of these pigments is not an "on" or "off" matter as one would expect if one locus was at the heart of the process. I have made the repeated argument that the "recessive" character of blondism and the "dominant" character of brunette hair is partially an artifact of how we classify hair color. All the various non-blonde hair colors, from brown to black are slotted into the "dominant" category, when I would argue that even among black haired people there is a wide variance of pigment concentration of eumelanin that visual inspection might miss, for example between a light skinned Japanese individual and someone from southern India or Africa (basically, one can not get below a certain level of reflective, so all the extra melanin does not register any change in color).

Now, to the Australian Aboriginals.

1) The perception (based I assume in color plates in older anthropology books) that the blonde Aboriginals were ash in their coloration is correct. The reason, according to Birdsell, is that they exhibit very little pheomelanin in their hair. Of course there is a lack of eumelanin in the hair samples as well. Unfortunately Birdsell did not assay the concentration of granules quantitatively, but inspected them visually under a microscope. Nevertheless, he saw what was going on at the proximate level pretty well. It wasn't, to consider an outlandish example, a case where a yellow pigment was being produced that obscured the eumelanin.

2) There is both sexual dimorphic and paedomorphic tendencies to the trait. In short, pre-pubescent children are blonder, as are females.

3) This is not a rare trait that is expressed by a few individuals in many tribes. Rather, the frequency of the phenotype can approach 90-100% in children, and still remain significant even in adult males. Also, the "darkening" is often to a brown color, rather than black.

4) Birdsell suggests that the allele which causes this blondeness, in reality the loss of function or expression of both traits (dark and red pigment), is characterized by "incomplete dominance." The frequencies for the expression of the trait are extremely high. If it was a "recessive" trait the allele(s) must be close to fixed. I don't find his arguments persuasive because he didn't mention crosses between dark haired aboriginals and blonde aboriginals, in part because the unmixed peoples of this sort (that is, without European ancestry) are also not likely to go on cross-continental searches for husbands or brides from other Aboriginal groups. But, that being said, Birdsell offers the following observation: hybrids between Europeans and dark-haired (eastern) Aboriginals never exhibit hair that is lighter than brown. Obviously, not all Europeans are blonde, or carry blonde genes, but the conclusion of blonde phenotypic recessiveness is hammered home. Hybrids between blonde Aborigines and Europeans almost always exhibited the ash blonde phenotype of the Aborigines as children. I don't put too much stock in terms like "incomplete dominance," aside from that it is saying "hey, we don't know much about this gene." Nevertheless, I think the hybrid phenotype is a strong line of evidence that it isn't localized on the same part of the genome as the blonde loss-of-function alleles in Europeans. Crosses between dark haired Europeans and blonde Europeans do not almost always result in blonde children (many times the children are blonde and they become dark haired as they develop, but, Birdsell seems to suggest that inheritance pattern is more deterministic when one of the parents is an Australian Aboriginal blonde).

5) Birdsell notes that the blonde phenotype does not apply to all body hair. Almost all the rest of the body hair is rather dark, the only exception being the hairs on the forearm, which tend to be even blonder (that is, those who darken with adulthood retain blonde forearm hair).

I would like to end with a tentative hypothesis. Obviously Birdsell is trying to convey the impression that this is a trait that is "incompletely dominant," even though it is a "loss of function" trait (eumelanin and pheomelanin seem to not be found in the hair). The "incompletely dominant" part suggests that there is a locus of large effect at work here. Additionally, Birdsell only mentions gradation in hair color as a function of development or maturation, not population. What I mean by this is that one doesn't get the impression of individuals with light brown or dark blonde shades as youth who become black haired as adults. Continuity (normalish distribution) is a feature of polygenic traits, while discrete or binary tendencies are exhibited by classical mendellian traits. With this in mind, I offer that perhaps these Australian Aboriginals carry an allele which results in the synthesis of a trans-acting factor which suppresses gene expression on the loci which control for melanin production (or, it could be interfering with a crucial regulatory step). This suppression is obviously dependent on factors relating to development and cell-cell differentiation, because the melanin is found in copious amounts in other body hairs as well as in the skin. A sequencing of the loci which we know affect melanin dosage might not turn up anything out of the ordinary in comparison to other dark skinned people. In contrast, I suspect many Europeans have multiple polymorphisms which result in the overall reduction in melanin production via melanocytes throughout their skin, their body hair as well as their irises.

So why is this trait expressed in frequencies of 90%+ (that is, adults who started out ash blonde as youth) in the west-central deserts of Australia? Birdsell doesn't offer any selectionist reason, and I can't think of any environmental ones. There was obviously constraint on skin color, which makes sense in light of the protection that dark skin confers against radiation. The only thing I can come up with is sexual or social selection (ie; it might have been preferences for a particular type of child as opposed to males and females choosing each other for this trait). But it is basically a default hypothesis (I do not credit genetic drift in this case, but I do not know the demographic history of these tribes, so that is a possibility I suppose). Also, blondism might just be a byproduct of the allele's function, which we do not know yet (or, we know it, but have not made the connection).

I was going to scan the map up, but I'm having some driver issues, so no go in that direction (if someone wants to find the book and scan it up and put it on flickr I will link to it-it's on page 196). Descriptively, you have a modal frequency of this phenotype in the middle of western Australia of 90-100%. The frequency drops off to around 50% by the southwest coast and the geographic center of the continent, and more sharply north toward Arnehm Land until the phenotype is almost nonexistent on the north coast. The phenotype is absent from the eastern third of the continent. Overall, one can imagine an area of the map where the phenotype is absent like a crescent, thick and rotund in the southeast, and becoming a relative sliver as it arcs around the zone of blondeness around its northern edge.

Related: Black and strawberry.

1 - p2 + 2pq + q2 = 1. The "recessive" allele is usually signified by q. The q2 is the frequency of expression of the recessive phenotype, so for example, if the blonde allele is present in a frequency of 0.5 throughout the random mating population, 1/4 of the individuals will express it. If a population is 1/2 blonde, than 70% of the alleles floating in the population are blonde. So, if you had a tribe that was 50% blonde, if blonde alleles are neutral (no selective advantage), ignoring drift one could assume that 70% of the ancestry was European if the alleles had to have come from that source population. Of course, I don't think that the dominance-recessive concept really works well a lot of the time, and I certainly don't think that blondism is a one locus mendellian trait, contrary what they taught us in high school.

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