Since Chad Orzel hasn’t posted on it, I figured I’d link to this story about a Nature letter which announces the discovery of a planet 5.5 times as massive as our own! This is pretty cool, I was a big fan of astronomy when I was a kid, and it certainly is the science with tickles my “shock & awe”-o-meter. But combined with the possibility of sub-thousand dollar genomes in the next 5 years, it really does make me feel like we are at the End of Times and soon we shall be as gods. OK, that was a hyperbole, but I can dimly grok the difficulty of a extrasolar detection feat like this….
Update: Chad comments copiously now.

Judith Rich Harris is author of The Nurture Assumption and the forthcoming No Two Alike: Human Nature and Human Individuality. Her controversial thesis is that parents don’t matter, genes and peers do, in making you who you are as a person. You can read my Q & A with her over at my other website. Here is the paper (PDF) that started it all….

I was in Cambridge for a weekend, and I made up this saying (after consultation with friends who are grad students at Harvard and MIT):

Harvard students know how to seem smart
MIT students know how to be smart

And while I’m at it, I just thought of this:

Know the name of your enemy
But nothing else about them

Addendum: The point about Harvard vs. MIT wasn’t that MIT students are endowed with a non-trivially higher quanta of general intelligence. What I was trying to get at is a point I was discussing with a friend of mine who admires the humanities, but is himself a physical scientist at MIT, one can make humanities majors difficult, but it is not a necessary corollary of that course of study. This was brought home to me when I was discussing grading with a friend who is an instructor at Harvard in a humanities field who expressed frustration at the bullshitting tendencies of his students. He wanted them to work harder and express real thoughts instead of what he assumed they assumed would get them the A with the lowest amount of effort. Being verbally exceptional and always expecting and getting the highest grades, there was a lot of pressure to give those grades out no matter the substance of the material (the impression I got is that the style and presentation were always top notch and reflexively produced). In contrast, in the sciences you either fail or you don’t, you can’t really bullshit your way out of solving a heat flow problem if you forgot your differential equations. The sciences, especially those requiring a lot of mathematics (physics, engineering, etc.), impose a floor of minimal competency which is capable of taxing normally bright individuals (i.e., ~140 IQ).

This article about the halting of land development in Scotland because of “fairies” under a rock is illustrative. When comparing nations in regards to belief in the paranormal we often assume that “modernity” and education have banished magical thinking. I don’t believe it is so, rather, magic is still there, ready to surface when given an opportunity. Many would commend Europeans on their acceptance of evolutionary theory, but it is important to note that surveys of public opinion on the other side of the Atlantic suggest a folk far more demon-haunted imagination than one might suppose (search within the PDF linked above for “astrology”). I have noted before that cognitive anthropologists have long posited that our mental biases are synthesized in a fashion so that we are predisposed to see ghosts, believe in supernatural gods and the existence of an afterlife. The difference with Creationism in the United States is that a strong streak of intellectual populism taking strength from organized evangelical Protestantism has rejected the elite counterintuitional consensus (in this case derived from established science), and has generated a counter-paradigm which strongly appeals to preexistent intuitions. This is why I suspect that the fight against Creationism in the United States is going to be the work of generations, the counter-paradigm is evolved toward being intelligible because of the cards evolution has dealt. In contrast, moving beyond a belief in evolution (i.e., simple acceptance of the legitimacy of scientific specialists) to understanding the process requires mental output, putting evolutionary theory at a psychological disadvantage in a world where time and energy are finite. This may explain the obfuscation I have observed amongst the new Creationists, the more technical they can make the discourse the greater skepticism they can engender in the public until finally they simply accept their intuitions as the default option, which strongly biases them towards Intelligent Design or one of its iterations.¹
1 – Humans possibly possess an agency detection mechanism, so any design based theory starts out with an advantage since design intuitively implies agency (The Blind Watchmaker explains why design does not necessitate agency, but most people have neither the time nor inclination to read 400 pages of exposition that will throw cold water on their ‘common sense’).

Judith Rich Harris is author of The Nurture Assumption and the forthcoming No Two Alike: Human Nature and Human Individuality. My questions are in bold.

1) One criticism some of my readers made about ‘The Nurture Assumption’ is that it did not take evolution into account enough, will we see more evolutionary-historical considerations at play in ‘No Two Alike’?

Yes, there is quite a lot about evolution and evolutionary history in No Two Alike.

2) Do you believe cognitive psychology has any insights into why people seem to have a strong bias in asserting the overwhelming role of family in the character of a child? Or do you believe that this is a cultural innovation?

Cultural factors are certainly involved. Americans didn’t always have this strong belief in the role of the family – in particular, the role of the parents – in shaping a child’s personality and behavior. That belief became popular around the middle of the 20th century. Prior to that, when children were troublesome or otherwise disappointing, the general consensus was that they were “born that way.”

But there may be a cognitive component as well. There is a cognitive bias that makes people overestimate their own importance and their own ability to influence how things turn out – not just in child-rearing but in everything they do.

3) In ‘The Nurture Assumption’ you argue that children’s peer groups are more influential on their behavior than their parents. One of your key illustrations of this is the fact that children of immigrants quickly acquire the language and accent of their non-immigrant peers. But it might be objected that this is a special case, as children have a specific ‘language instinct’, in Pinker’s sense, which governs their language acquisition. What would you reply to this objection, and do you have any equally good alternative examples of peer-groups prevailing over parents?

The language instinct can explain why the child of English-speaking parents learns to speak English, but it cannot explain why, if this child goes outside and discovers that the people out there are speaking a different language, he not only acquires that new language but comes to favor it over the language his parents taught him – a language he still speaks at home.

But I can give you some examples that don’t involve language. Robert McCrae found that there are personality differences between people reared in different cultures. For example, North Americans are somewhat more outgoing and less agreeable, on average, than Asians. McCrae gave personality tests to Asian-Canadian college students, the children of immigrants from Hong Kong. He found that the students who had recently arrived in Canada had personality profiles similar to those of the people back in Hong Kong, but the Asian-Canadians who were born in Canada were similar to other Canadians. Those who had arrived in childhood were somewhere in between. So the culture of the home – the culture the parents brought with them from Hong Kong – wasn’t what determined the offsprings’ personality. The children who were raised in Canada became Canadians.

My second example has to do with neighborhood effects on behavior. Researchers studied two groups of African-American school-age boys. These children all came from the same kind of home: low-income, headed by single parents. But some homes were located in black, poverty-level neighborhoods, and others were in neighborhoods that were predominantly white and middle-class. The researchers found that the African-American boys living in poverty-level neighborhoods were highly aggressive, but that those living in middle-class neighborhoods were no more aggressive than their white,middle-class peers. In both cases, these children had adapted their behavior to the local norms.

4) In your 2005 response to the Edge Question, “What Do You Believe Is True Even Though You Cannot Prove It?,” you alluded to two things, 1) selection for light skin 2) hairlessness by parents in infants. When you pointed to these facts, did you do so in light of recent genetic work which suggests that dark skin might have evolved in humans as a response to loss of body hair? In other words, one trait would never been selected for if not for the other.

No, I hadn’t heard of that work. But it doesn’t matter. All humans have more or less hairless bodies, so I assume that the characteristic of hairlessness is at least as old as our species – at least 100,000 to 200,000 years old. Racial differences in skin color, on the other hand, are no more than 50,000 years old. If humans turned dark-skinned as a response to hairlessness (a theory I find dubious), then an explanation is still needed for why their skin turned white again so quickly when they inhabited Northern Europe, thousands of years later. My response to the 2005 Edge question offered a possible explanation.

By the way, I’ve expanded that essay into an article for a journal called Medical Hypotheses. It will be published in a few weeks.

5) Research that compares correlations of adoptive/biological families (mostly done by a handful of American behavior geneticists) typically finds low shared family influence, but research that compares means of adoptive/biological families (mostly done by a handful of French sociologists) typically finds big roles for genetics and shared family. Is correlation a reliable method for saying there is no shared family influence, might means need to be given more weight by behavior geneticists?

You’re talking now about the effects of adoption on IQ. First, let me make it clear that all these studies showed a big role for genetics. Second, I agree that American behavioral geneticists might have underestimated the influence of “shared environment” (the environment that siblings raised in the same family have in common) – not because they’ve ignored means but because the adoptive homes these researchers looked at tended to come from a narrowed range: adoptive parents are generally middle- or upper-middle class. The French researchers, on the other hand, made a special effort to include lower-class families in their studies, and hence found a larger influence of shared environment. These results, by the way, are consistent with those from the behavioral genetic study of reared-apart identical twins: no influence of shared environment on personality (the correlation between the reared-apart twins was the same as that between the reared-together twins), but a small influence of shared environment on IQ (the IQ correlation was higher for the reared-together twins).

But I have a quarrel with the way you phrased your question: you said that correlational studies typically find “low shared family influence.” What the researchers actually find is low influence of the shared environment. The environment shared by reared-together siblings doesn’t just include the family: it includes the neighborhood, the school, the ethnic group, and the socioeconomic class. Sometimes siblings even belong to the same peer group. In other words, reared-together siblings share a culture or subculture.

My interpretation of the IQ data can explain both the means and the correlations. Here’s how it goes. The family does have an effect on IQ during childhood. If the parents use big words or do various other things that increase a child’s vocabulary, the child will score higher on IQ tests. But research has shown that this advantage – measured as an effect of shared environment – is temporary: it gradually fades away and is gone by late adolescence.

What isn’t temporary is the advantage given by a culture (or subculture) that fosters intellectual activity. At higher socioeconomic levels, there tends to be a greater awareness that things like reading and going to science museums are good things to do and might pay off in the long run. So socioeconomic class does have a long-term effect on IQ. This is a cultural (or subcultural) effect and results in a difference in means: adoption tends to raise a child’s IQ because most adopted children are raised in middle- or upper-middle-class neighborhoods.

A similar cultural effect can explain the gradual increase in average IQ scores that has occurred in the last 75 years all over the world. All over the world, socioeconomic levels have gone up and people are more aware than they used to be that intellectual activities might pay off in the long run.

6) Has behavior genetics declared the death of shared environment prematurely without considering levels of “shared environment” that occur above family – neigborhood, city, state, country, etc? Also if these things matter (which seems indisputable) and are mediated by shared family (which seems indisputable), again are the correlations hiding important details of parental influence?

No, not at all. Most behavioral geneticists are well aware that “shared environment” can mean the environment siblings share outside the home, rather than (or in addition to) the family environment. For example, behavioral geneticists have found an effect of shared environment on teenage delinquency. But, as behavioral geneticist David Rowe showed, the evidence suggests that the relevant environment is the neighborhood or school shared by teenage siblings. Siblings close in age may belong to the same peer group, and Rowe found that the shared environment effect on delinquency is larger for siblings close in age.

I see no justification for saying that the effects of shared environment are “mediated by the shared family.” There are things that may in fact be mediated by the shared family – cooking styles and religious denomination spring to mind – but for most of the things that behavioral geneticists have studied, the shared environment should not be equated with the family environment.

You ask if correlations might be “hiding important details of parental influence.” Perhaps what you’re getting at here is the notion that parents might influence one of their children one way and another child in a different way. For example, the parents’ child-rearing style might cause one sibling to become more outgoing and bold, the other to become more timid. If the direction of the effect depends on the preexisting (genetic) characteristics of the child, then what you’ve got is a gene-environment interaction. There’s a whole chapter (Chapter 3)in No Two Alike devoted to gene-environment interactions. I show why they can’t account for twin and sibling differences in personality.

But perhaps when you ask whether correlations might be “hiding important details of parental influence,” you are talking about sheer unpredictability: the notion that parents do have an effect, but there’s no way to predict in advance what the direction of the effect will be. Developmental psychologist Ellen Winner used this notion to explain away the behavioral geneticists’ findings, in her response to the 2005 Edge question. “To demonstrate parents’ effects on their children,” Winner said, “we will need to recognize that parents may influence their children to become like them or to become unlike them.” Winner suggested that researchers should study adult adoptees “and look at the extent to which these children either share their adoptive parents’ values or have reacted against those values. Either way (sharing or reacting against), there is a powerful parental influence.”

It’s a heroic attempt to preserve the faith in parental influence, but a futile one. What does it mean to say that parents do have a powerful influence but that the direction of the influence is unpredictable? Is there any way to prove or disprove that statement? Does it have any scientific value? For that matter, does it have any practical value? Would parents be satisfied to be told, “Yes, your parenting will have an effect on your children, but we can’t tell you what that effect will be”? It would mean that books of child-rearing advice would have to begin with a disclaimer: “If you follow this advice, your children might turn into happy, successful people; on the other hand, they are just as likely to turn into miserable failures.”

7) OK, to something serious, east coast vs. west coast, is there any comparison in weather?

Not according to my older daughter, who lives in Berkeley. Whenever I complain about the snow, ice, or cold here in New Jersey, she points out that where she lives, the weather is “sensible.”

8) How far do you go with ‘modularity’ in ‘No Two Alike.’ I ask because one of the questions of interest in behavior genetics is variation within a population. On the other hand evolutionary psychologists tend to emphasize human universals and the ‘psychic unity of mankind,’ often rooted in a paradigm of massive mental modularity which assumes that cognitive organs are fixed genetically (monomorphic) and not subject to non-pathological variation.

I go pretty far with modularity. I don’t think it’s possible to give a satisfactory description of social and personality development in childhood without thinking in terms of a modular mind. Simple theories of social development don’t work because the human mind isn’t simple!

You’re right that the behavioral geneticists are mainly interested in human differences, whereas the evolutionary psychologists are mainly interested in human universals. But that distinction is starting to crumble. In his book The Blank Slate, evolutionary psychologist Steven Pinker has a chapter (Chapter 19) devoted to individual differences.

As for the idea that “cognitive organs are fixed genetically…and not subject to non-pathological variation,” I think it’s nonsense. There is variation in all our essential organs. Why should my language acquisition module be identical to yours if there are differences in our hearts, lungs, kidneys, arms, and legs?

9) If you had to pick one thing, what do you think has been the most important finding from cognitive neuroscience which psychologists have had to take into account in formulating their theories?

In cognitive science, I would definitely pick modularity. But in psychology in general, I think the most important finding is the behavioral geneticists’ discovery that the environment doesn’t work the way everyone expected it to. Shared genes, as expected, make people more alike; but shared environment, to everyone’s surprise, hardly ever makes people more alike. To put it another way, having different environments – growing up in different homes, being reared by different parents – isn’t what makes people differ from one another. So what does make them differ? That’s the mystery I try to solve in No Two Alike.

10) If you could have your full genome sequenced for $1000, would you do it? (assume privacy concerns are obviated)

I’d jump at the chance, and I wouldn’t give a damn about privacy concerns – I’d want the information to be made freely available. My father spent his adult life crippled by an autoimmune disorder called ankylosing spondylitis. His father died young of an autoimmune disorder called pernicious anemia. And I have been ill most of my adult life with an autoimmune disorder that has launched attacks on several different body systems. So I think my genes might have something interesting to tell medical researchers.

A few weeks ago Edge.com asked prominent thinkers what their Dangerous Idea was. The poser of the question was Steven Pinker, and he’s on Radio Open Source today (you can listen on the web, wait ’till 7 PM EDT). I offered my 2 cents in the comments, the basic gist of which was that the explosion of information and the ability to access it in the modern world makes secure understanding and knowledge more difficult than in the past. Professionally obfuscatory paradigms like Post Modernism and neo-Creationism can arise precisely because trust and good faith are more crucial in a world where one person can’t understand even one discipline in depth.
Another point I also wanted to make is that there are two genres of “Dangerous Ideas,” ideas not particularly dangerous in academia but dangerous in the context of the wider culture, and ideas that are universally verboten. All those who assert rejection of the soul and free will are dangerous ideas also know that the former is probably normative among many intellectuals, and the second is not particularly revolutionary, both philosophy and religion have examined it for centuries. Now consider Pinker’s response, the first part in regards to sex differences is probably widely accepted outside of academia, while the second portion in regards to intergroup differences tracking race or ethnicity has been a cultural third rail for several decades. I believe that understanding of some intergroup differences more salient than lactose digestion capacity will arise out of the genomics, and there are already hints of this in the HapMap. I suggest intellectuals now move to making the public more conscious of probability distributions and bayesian logic.
Update: A reader would have you know that I was noted as the “best comment” on the thread for this particular episode of Radio Open Source. The archives aren’t up yet, but just go to their site and scroll down their left bar, it should be there soon. About 45 minutes into the show Brendan reads comments from the thread and states that I had the best one 🙂 Seed doesn’t pay me the big bucks for nothing!
Update II: OK, listen here (24 MB mp3).

Nicholas Wade did an interview with PLOS Genetics a few months ago. You might be interested, as he has a new book coming out, Before the Dawn: Recovering the Lost History of our Ancestors. I am doing a review for a magazine so I have a copy, and the galley has a lot more in it than the history of our ancestors (think his sequence of articles over the past 5 years). I suspect it will be marketed like Spencer Wells’ book, but this is a different beast altogether.

Nature Reviews Genetics has a review of the emerging evidence for massive amounts of structural variation in the human genome.

Abstract:

The first wave of information from the analysis of the human genome revealed SNPs to be the main source of genetic and phenotypic human variation. However, the advent of genome-scanning technologies has now uncovered an unexpectedly large extent of what we term ‘structural variation’ in the human genome. This comprises microscopic and, more commonly, submicroscopic variants, which include deletions, duplications and large-scale copy-number variants – collectively termed copy-number variants or copy-number polymorphisms – as well as insertions, inversions and translocations. Rapidly accumulating evidence indicates that structural variants can comprise millions of nucleotides of heterogeneity within every genome, and are likely to make an important contribution to human diversity and disease susceptibility.

Summary:

* Structural variants in the human genome include cytogenetically detectable and submicroscopic deletions, duplications, large-scale copy-number variants, inversions and translocations.
* The ability to detect and characterize structural variants in the 1-kb to 3-Mb size range in a robust manner across the genome has not been possible until recently.
* New developments in genome-scanning technologies and computational methodologies, and the availability of a reference sequence for comparison, have made possible the large-scale discovery of structural variants.
* Many studies are revealing that the total content of structural variants in the human genome could equal or exceed that of SNPs.
* Structural variants often coincide with low-copy repeat DNA (also called segmental duplications), as these highly related sequences are more likely to undergo non-allelic recombination and subsequent rearrangement.
* Structural variation in the genome can directly or indirectly influence gene dosage through different mechanisms, and therefore influence phenotypic variation and disease.
* The cataloguing of structural variants and their frequencies in populations will be important for disease-mapping studies and for proper interpretation of clinical diagnostic-testing data.

We’ve mentioned some of these large scale variations before.

There has been talk about cannibalism on this weblog before. A school of anthropologists have been trying to argue for a few decades that legends of cannibalism are simply myths that are used to dehumanize the “Other.” Some scholars, like Jared Diamond, disagree with this assessment very strongly and assert that the analysis is not only faulty, but biased by the tendency of some anthropologists to see noble savages where there aren’t any. The cannibalism-is-a-myth thesis has some appeal, Martin Gardner, contributor to The Skeptic, found the idea plausible. I say “found” because I suspect that Gardner was convinced (I don’t know if he’s commented on the topic of late) by the genetic evidence which suggests selection for prion resistence could be detected in many human populations. This is a nice way that genetic evidence can be used to supplement the discourse in other disciplines, especially in fields where the exchanges are somewhat value-laden and emotionally explosive. Another example would be the likelihood that the crypto-Jews of New Mexico might actually have non-trivial Jewish ancestry. The contrarian skeptical bent in cultural anthropology was to explain these stories as myths generated by particular social biases and the relicts of attempts by Seventh Day Adventists to convert Latinos in the American Southwest in the early 20th century (ergo, Jewish ritual traditions). This explanation received featured space in The Atlantic Monthly in the late 1990s, and I accepted it simply because it seemed less sensational than the alternative.

Nevertheless science doesn’t have the surety of God. A new paper disputes the findings in about the history of cannibalism in regards to the magnitude of the practice, though I think the general thrust (that cannibalism is not a myth) remains standing from what I can see (link via Abhi). I’ve uploaded the file as “cannibal” in the forum, jump to the discussion to see what I mean by rejecting the extent but leaving open the plausibility of this practice locally.

Related: Researchers Find Mutation In Lincoln’s Family.

Yesterday I was talking to a friend of mine who is a graduate student at a university in Cambridge, Massachusetts, in the department of “Organismic and Evolutionary Biology.” My friend asserted that most people within her department are dumb, overbearing, arrogant and uninformed. Her concern was that this was within a department specializing in evolutionary theory at the nation’s elite university!
Then we got to talking about Intelligent Design, and I mentioned how a link from The Corner resulted in an influx of Intelligent Design proponents on my other weblog. Now, as a kid growing up in a conservative religious part of of the country I’d debated Creationists many times. I knew their tricks, from the Second Law of Thermodynamics to the Moon Dust argument. But what I encountered this time was a new species. I was greeted by an assault from the technical end of molecular & population genetics. An individual was asserting that Fisher’s Fundamental Theorem of Natural Selection showed that evolution was not viable as a long term project. In short, this theorem states that the rate in increase of fitness is proportional to the additive genetic variation. Since selection on this additive genetic variation should exhaust the variation itself, over time the change in fitness should approach zero as variation is depleted. But this ignores the reality that mutation (and sometimes migration) can replenish additive genetic variation, and it neglects that many evolutionary population geneticists are skeptical about the widespread applicability of the theorem beyond one locus. Now, not getting into issues of mutation-selection balance and what not, the fact that a neo-Creationist tried to pull this trick on me was shocking and disturbing, because I’m skeptical that many intelligent people would have a cogent response. The individual even tried to spin some talking points out of the neutral theory of molecular evolution.
The reality is that this is simply a variation on the Second Law of Thermodynamics tactic, memorize some technical issue and try to bluff your way through the debate. Fortunately, I wasn’t taken in, and many of my readers have enough evolutionary genetic saavy to see the game for what it is, but, this sort of behavior is grossly undermining of the attempts to engage in good faith science. The fact is that no one human can master all technical aspects of the world and we have to rely on experts who we assume understand what they are talking about. When neo-Creationists and their ilk inject themselves into the discourse, and confuse and deceive those outside the technical circle, the noise in the system of science increases greatly. Ultimately the complexity and technicality of modern science means that it is difficult for anyone to attain a gestalt understanding of whole fields and theories, let alone multiple disciplines. Good faith, sincerity and honesty¹ play crucial lubricating roles in the process of knowledge acquisition and model building, and the neo-Creationists sacrifice all of these in the service of a greater God. Which gets me back to where I started, many scientists are bullshit artists. They get where they get often because of political skill and good verbal repackaging of derivative work. Marry that to the mercenary intellectual outlook of the neo-Creationists and I think we are likely to see an escalation of the “conflict” between science & non-science in the next few decades. The Creationists are evolving….
1 – What about reproducibility and peer review you say? Talk to Hwang Woo Suk. The system of science is corrective in the long run, but its efficiency is still contingent upon the parameters I pointed to above.