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John Jay Ray points me to this paper titled Mathematical giftedness and family relationship. I suspect GNXP readers might be curious….

23 Comments

  1. In what I read there didn’t seem to be any attempt to factor out the “nurture” side of the equation. The reverse, really — occupational status (~ social class)was used as a proxy for family IQ, which was not even measured.

    In my anecdotal observation of HS students, the biggest factors leading to success seemed to be a strongly positive attitude of the parents toward education, and respect (in the sense of obedience) of the students for their parents. I have known of very poor, not-well-educated immigrant parents whose kids went to a mediocre school and did extremely well educationally for this reason (ending up in med school, for example).

    There’s a second level of nurture which leads to the whizzes — parents who are already well-educated and take steps to give their kids an enriched environment. Kids like this are not really dependent on the school at all (though a good school helps, eg lab resources) and often end up doing professional level work while in HS (the science fair type kids).

    Brad DeLong, an economist and economic historian with broad interests, frequently posts samples of his converstaions with his kids on his site. He found out that his kids (7 and 10) were not were interested in mathematical approaches, though they loved science, so he’s been digging up mathematical puzzles and games to get them interested.

    Musical prodigies usually come from families where music is the family business. The Mozarts, Haydns, and Bachs all had ongoing musical traditions. (Leopold Mozart was a specialist in pedagogy; Wolfgang was his guinea pig. Wolfgang may have been a better musician than Leopold simply because he was taught better).

    I am not dogmatic about the heritability of intelligance and temperament, but the attempts to factor out nurture often seem perfunctory.

    Cases of fosterage or adoption would provide an interesting but ambiguous test. Sometimes a bright kid of humble origin is fostered into an educated family and does very well. So his nurture is from the educated adoptive family, while his genes are from an uneducated lowly family. On the other hand, prodigies are so accomplished that it seems inborn. So maybe it’s a hereditary ability which is almost randomly distributed.

    Some think that Karl Friedrich Gauss was the greatest mathematician of all time. “Gauss was born in Brunswick, Germany as the only son of poor peasants living in miserable conditions. He exhibited such early genius that his family and neighbors called him the “wonder child”. When he was two years old, he gradually got his parents to tell him how to pronounce all the letters of the alphabet.”

    I really believe that most people have more intelligence than they need or want and that they learn to be stupid. This is not an argument against heritability at all, but something to think about.

  2. In my anecdotal observation of HS students, the biggest factors leading to success seemed to be a strongly positive attitude of the parents toward education, and respect (in the sense of obedience) of the students for their parents.

    Evidence shows that parenting has very little to do with the long-term success, intelligence, personality, or mental well-being of children. This is fairly well established*. This doesn’t mean environment isn’t important- it is -it just means that you’re probably looking in the wrong one. (what the_right_one might be, is a trickier question)

    We have had some amazing results from a good number of adoption studies (plomin still regularly publishes fascinating evidence from these studies), that show a substantial degree of heritability. Adoptees are wildly more similar in measured IQ to their biological parents who they have never met (.30) then they are to their adoptive parents who raised them where the correlation hovers around .0!**

    *http://www.apa.org/journals/rev/rev1023458.html

    **Horn J.M, Loehlin, J.C, & Willerman (1979), Scarr & Weinberg (1978), Plomin, R., & Loehlin, J. C. (1989)

  3. I am highly suspicious of the idea that parenting does not affect children. I know that there’s a book floating around which I haven’t read; from the things people say it seems like fairly tendentious and rather mushy social science.

    As I’ve said, probably because of their weak study of areas outside their specialties, what I’ve read from the “nature” side of the argument seems extraordinarily weak in factoring out the nurture side. Isn’t my criticism of this particular study valid? Using parent’s occupation as a proxy for IQ simply begs the question. That’s an example of the kind of thing I’m talking about, and that’s why I posted here at all.

    Look at the Haydn, Mozart, Bach, and Gauss examples. Would Mozart have done the same with a different father? And where did Gauss’s genius gene come from?

    A major point of mine is that talent expresses itself if it has a venue to express itself in, and if not, not. Gauss was extremely lucky to be in a place where education was available, for whatever reason, even to the children of peasants.

    This is something that parents can do something about. (Suppose a parent deliberately moves from a place with poor or no public schools to a place with excellent schools. Will this have an effect on the kid? This is a different thing from saying, for example, that nice parents can raise kids to be nice, or that parenting-style A has good results and parenting-style B bad. In other words, more is involved in nurture and parenting than just the face-to-face personal relationship with the parent; the parent also can influence the environment away from home).

    The successful kids I’m talking about were kept by their parents in a controlled environment within which good things happened if they got good grades and bad things otherwise. They had concrete incentives to work at school, so they did. This probably did not increase their IQ, but a lot of the political IQ debate is about some groups which are productive and successful and others not, with the assumption that unproductive groups are low-IQ. Whatever their IQ (probably average) these kids were going to be productive.

    Substitute a very bad, neglectful, abusive parent. Even if good parents can’t do anything good, bad parents can certainly do harm. Frankly I think bad parenting could lower IQ itself by creating someone so fucked-up that they’ll never be able to pay attention to a test. IQ as we know is a test result.

    I have known two people who decided that their own personal problems were genetic and failed to look at non-genetic aspects which were obvious to everyone else. I have also known a mother whom almost everyone would call neglectful and abusive who decided that her son’s problems were physiological and got him drugged up. There are a lot of political balls in the air on these scientific questions and that’s really the way it has to be.

    I have no doubt that there is a major heritable component to intelligence. I am agnostic about the racial distribution of intelligence. The political debate about hereditable intelligence seems to overstate intelligence as the primary decisive factor in life while failing to control at all well for nurture. And the political-football aspect of the question isn’t going to go away, and it shouldn’t either. There’s a lot at stake.

    Godless capitalist: once this kind of thing is actually expressed in non-hypothetical genetic terms rather than just statistically, yes, people’s minds will be changed. I’m not enthusiastic about the experiment you suggested, though. One thing I’ve always been suspicious of in genetic explanations of behavior or IQ is the extreme thinness of the science compared to what I have seen in, for example, the genetic explanation of hemophilia.

    Twin studies: I once knew an Indian-American twin whose sister was raised in India as an Indian. You sort of wish that some of the many Korean orphans adopted into the US had twins back in Korea. As I said, I’m not a skeptic about the heritability of IQ.

  4. Look at the Haydn, Mozart, Bach, and Gauss examples. Would Mozart have done the same with a different father? And where did Gauss’s genius gene come from?

    g!=genius. a high IQ is probably a precondition for prowess is high mathematical fields like being a college math professor (duh!). but, the same person under different circumstances might decide to become a lawyer (look at eugene volokh, his dad is a math professor and he got a degree in computer science before he switched to law) or foreign policy analyst (paul wolfowitz). additionally, jensen indicates that the threshhold effect is important, that an IQ of 130-140 is probably a necessary condition for excelling in certain fields, but that once that threshhold is crossed, other factors, like passion & focus also become important. so i would say you are comparing oranges to tangerines here-geniuses (math ones at least) are probably a special subset of high IQ individuals.


    Suppose a parent deliberately moves from a place with poor or no public schools to a place with excellent schools. Will this have an effect on the kid? This is a different thing from saying, for example, that nice parents can raise kids to be nice, or that parenting-style A has good results and parenting-style B bad. In other words, more is involved in nurture and parenting than just the face-to-face personal relationship with the parent; the parent also can influence the environment away from home

    jason will point it out, but your assertion here is one of the major points in the …fairly tendentious and rather mushy social science…. you referred to earlier.

    I have no doubt that there is a major heritable component to intelligence. I am agnostic about the racial distribution of intelligence. The political debate about hereditable intelligence seems to overstate intelligence as the primary decisive factor in life while failing to control at all well for nurture. And the political-football aspect of the question isn’t going to go away, and it shouldn’t either. There’s a lot at stake.

    i’m not quite getting your objection, and i don’t see the deemphasis on nurture you are talking about. on the level of the street people do tend to be genetic determinists in a rought sort of way (charles’ murtaughs moron majority). in contrast, the elite babble-culture tends to ignore genetic determinants (i suspect quite often because their endowments that are genetic are things they take for granted and want to assert that their success is the result of their hard work only). this dissonance causes a great deal of confusion in our society. GNXP tries to rectify that by providing a genetic explanation on a somewhat non-prolish plane. that doesn’t mean we don’t think nurture is important.

    let me give you a personal example-neither my brother or i are believing muslims. my father exhibits the same anti-clerical reflexes and iconoclastic anti-theistic aversion we both have on occasion, but in general, he is a moderate muslim. of course, my father was raised in bangladesh, i was raised in the united states, my father is a moderate muslim, his father was a koran scholar. the environment obviously had an impact. my brother is graduating with a degree in physics, i have a degree in biochemistry, my father is a physical chemist. you could say that environment effected us a lot. but much of the aspect of my personality that has come to resemble my father has manifested itself after i left home in college, in non-parental contexts. you could assert that my fathers shaping of my life was crucial. but there are some important points to be made-my father was in graduate school from when i was 5 to 11. i rarely saw him. i saw him so little that i did not know he was a scientist until i was 12! my father lived in a different state for 3 years when i was in high school. but your point is correct, my father chose what culture i was going to be raised in-and that really influenced me. he did not censor what library books i read, etc. etc. etc.

    well-i’m sure jason will get back to you-but i am skeptical of this claim that the newer theories are mushier than the older ones. :)

  5. ziz,

    I am highly suspicious of the idea that parenting does not affect children. I know that there’s a book floating around which I haven’t read; from the things people say it seems like fairly tendentious and rather mushy social science.

    I’m sorry, I didn’t mean to give you the impression that I was challenging you on the linked essay- I haven’t read it yet, so what you say may have quite a bit of weight. I also didn’t want to prove heritability, which I usually just assume people are comfortable with to some degree unless they say otherwise. I just wanted to point out that your experience of parents attitudes on education having the biggest effect on success probably doesn’t apply to the larger picture.

    This isn’t coming from the book of which you speak*, which exists b/c it has a theory about what part of the *environment* influences kids, not b/c it says parents aren’t a very big environmental influence. A look at any two siblings raised under the same roof suggests that much; as they are found to be as basically different as any two kids raised in different households** (and when genes are controlled for, no similarities are found at all).

    That parents can have bigger effects on their children through things like abuse or, like you say, moving to troublesome ghetto or rural regions is something I won’t dispute. I do think parents can have big indirect influences in matters such as the latter, but i was more responding to the efficacy of direct things such as parents attitudes towards education, or even DeLong’s math puzzles, and how those types of things effect people in the long-term.

    *and “mushy” or not it got some net positive reviews in the science mags and journals

    **and that includes things such as attitude towards education (which you would expect to have correlation when they are raised by the same parents with the same views toward it)

  6. Razib wrote:

    “in contrast, the elite babble-culture tends to ignore genetic determinants (i suspect quite often because their endowments that are genetic are things they take for granted and want to assert that their success is the result of their hard work only). “

    Also there seems to be a universal tendency to view everyone else as being similar to oneself. Many smart people cannot imagine that people think more slowly than they do, so they attribute stupidity to poor rearing or poor personal choices. Likewise many stupid people think that by working harder they could be achieve the same results as intelligent people do, and attribute their own relative failures to laziness. Smart people often enjoy performing complex intellecual tasks, whereas stupid people who attempt them will experience the pain of hardship. This may explain why many smart people do their homework whereas many stupid people do not, and this ends up propelling the idea that laziness is to blame for academic failure and the complementary idea that good parenting is responsible for success.

  7. My suspicion of mushy social science is pretty general, especially if the social science is psychology (not really a social science, I know. So, no, I don’t claim that my point of view has been proven by science either.

    In my own family the birth-order factor was very strong and as a result, the nurture was not the same. (As oldest I was heavily favored but also got the brunt of my father’s weirdness). Once you get into stuff like that the butterfly effect and complexity theory pop up creating unique micro-environments and making “control for nurture” markedly more difficult.

    If I read what you write about “parents not affecting their kids” correctly, what was meant is that most of the things that parents deliberately do to control their kids’ development don’t work very well. That’s true of many things in life and I can accept that.

    In the case of Gauss, supposing that he had not had the opportunity, how would anyone ever have known that he was a genius? Is there a genius way of hoeing weeds and hauling shit?

    My motives for being here are the Steven Jay Gould kind. Worldwide various sorts of hereditary innateness have always been used to justify the existing social heierarchy and make it permanent. Recent discussions of IQ have certainly tended that way. So I’m picking up the argument from that end, which I believe is a legitimate thing to do. As you can tell, I’m not all that sharp on the biological science end of this, and am not challenging what science there is on these question.

    I haven’t seen the gross manifestations of racism here that this site has been accused of, but given that IQ seems to be heritable, the sort of IQ elitism you have here, combined with racial realism, tends toward ratifying existing social inequalities as natural. (So I’ve outed myself, but I doubt I’ve fooled anyone). So I’m just poking around and trying to soften up the political end of what I see here.

    To me street-level genetic determinism is mostly a very bad thing. If you travel around the world you’ll often see it expressed about groups that can hardly be genetically defined at all (e.g. Catholic Irish in N. Ireland, or Serbs/Croats in the Balkans, or the Japanese pariah group which is genetically and linguistically indistinguishable from other Japanese). So I normally start off arguing for the nurture/ culture explanation. (I didn’t mean to imply that no one here regards nurture at all, but proportionately I would argue for more regard. This is a stereotyped terminology and argument, I know).

  8. Ziska:

    I agree in broad terms with your initial post. Parental involvement (*) is a key cause of intellectual development. In general, I think that first-order linear models between IQ and (income, educational achievement, ?) are hopelessly inadequate and ought to be abandoned.

    My parents were in the education business, and I was very aware of educational achievement as I was growing up. And, I have also taught chess (a high IQ activity for sure) to kids among other things.

    My experience has taught me that there are naturally gifted people and naturally disadvantaged people. For these, education has little if any effect in shaping their intelligence. The majority can really benefit from education, i.e., be taught to think more efficiently.

    Chess is like an IQ test, because you have to make a series of moves (questions) in a limited amount of time. Of course, in chess, one can always make a blunder and lose the game, but we can still analyze the overall quality of a player’s moves. My experience tells me that for the majority (not the extremes) the single most important element in chess success is education, not innate ability.

    (*) Especially maternal involvement.

  9. Men of Science,
    I have heard that personal interaction with infants e.g. cuddling, playing.. stimulates their mental development and can raise IQ points in comparison to neglected children. Are there studies measuring this? James Q. Wilson noted the relative lack of mother-infant interaction among African tribesmen. Even though the babies were fed and washed, mothers rarely tickled their feet, played peekaboo, or any of the the things that stimulate babies’ developing brains. This maybe the chicken and the egg problem, but might black Africans’ on average lower IQs be in part due to styles of infant care? And might this suggest that a mother who nurtures and stimulates her baby is in the long run more productive than one who dumps him at Daycare Emporium to write financial reports?

  10. So I’m just poking around and trying to soften up the political end of what I see here.

    It’s appreciated. If only more dissent was as well-mannered and level-headed as yours.

    Dienekes,

    Especially maternal involvement.

    The literature actually doesn’t show moms having much of an effect on the long-term intellectual outcomes, personality, or success of their children. As far as measures such as IQ and “love of learning”, interest in reading, and personality traits strongly associated with learning such as curiosity, etc. people just don’t seem to get much of these things from their developmental environments. This has been demonstrated repeatedly using twin, adoption, and regular family study experiments. (I’m not familiar with literature showing oterwise that attempts to control for genes)

    Also, to ziz, I’m pretty sure birth-order effects have only proved to apply to dynamics within the household,to the extent that they exist, but show not to apply at all to anything about a person once they’re outside the home (i.e no long term effects).

  11. Duende,

    I’m not aware of anything showing that a certain style of attention can raise the long-term IQ of babies. Jerome Kagan observed Guatemalan babies who were kept in almost total sensory deprivation for the first year of life and they were pretty fucked-up afterwards, but eventually were completely normal once exposed to a normal environment. African-American mothers, I am not aware, are especially neglectful of their children.

    But, One thing that has been shown is that breast-feeding can raise long-term IQ, and that AA mothers do have lower rates of brest-feeding. So I believe a promising boost could exist there.

  12. Jason Malloy:
    The literature actually doesn’t show moms having much of an effect on the long-term intellectual outcomes, personality, or success of their children.

    I wonder how maternal involvement is actually quantified in this studies.

    Also, the assumption that children being raised by the same parents, have the same environmental influence is inaccurate, (a) because of temporal difference, (b) because different kids are treated completely differently by parents.

    Also, the assumption that children raised by different parents are subject to fundamentally different environmental influences is also inaccurate. That does not account for the permeating “common culture” of a society.

    In general, intellectual development is a non-linear process with multiple causes. The published work on IQ has to use proxies for genes, and proxies for culture, or environment, because the raw factors themselves are unknown (as in genes), or not easily quantifiable.

    For example: two families may be a carbon copy to each other in terms of e.g., income, location, profession of parents, etc. creating a near-perfect scenario of testing the hereditary component of IQ. But, that makes no notice in how these nominally equivalent families actually work. The devil is in the details.

    The genetic component of IQ will be determined once genes conferring cognitive advantage are mapped and their effect is quantified. If I’m allowed to prophesy, I will say that I expect that there may be some mutations for genius, and some mutations for idiocy in the general gene pool, and only mild influence of genes for the majority of the population around the mean of the IQ distribution.

  13. Well, I’m quite different than all my siblings (six of them, and no, we’re not Catholic). More was expected of me, more given to me, I got more flak. Very little was expected of the youngest, and he was a self-destructive slacker until he was 32 or so. For example, my father tended to be arrogant and sarcastic, but I’m the only other who has those tendencies.

    In terms of expression of potential talent and ability of any kind, just as with language learning I think that there’s a critical period when you have to get actively involved or your potential is lost. My brother may have been originally bright but he never developed the habit of reading and now it’s hard for him. I also wasn’t interested in math when I was young, though I tested well, and now I’ll never be sharp in that. So I’m math-dumb now, but I don’t think I would be if I’d roused an interest at age 12 or 14 — I learned reasonably quickly to the extent that I was interested.

    In terms of development of abilities of any kind there’s an incredible amount of wasted ability. Most people originally have more intelligence than they end up using in their life. Stupidity can be taught and learned. (Not low IQ — I’m talking about normal or high-IQ people who work stupid jobs and watch lots of TV). So I’m less concerned about IQ shortage than wasted and unused IQ.

  14. Zizka:

    Speaking of wasted IQ, I recently wrote about a similar subject, namely that the achievement of societies and its dependence on IQ relies on societies making full use of their intellectual capital. And that, depends (a) on its goal-orientation, and (b) on its politico-cultural organization that may help, or hinder, the second-order inter-personal effects of social living that are simply not captured by the simple statistic of “average IQ”.

  15. I wonder how maternal involvement is actually quantified in this studies.

    You bring up many interesting questions Dienekes. Behavioral genetics has many tricks up its sleeve to try to answer them (these methods are necessarily imperfect, but IMO they are the best ways available to answer them) The best way to split up and understand the relative contribution of the effects of nurture and nature, and then to further split up the different kinds of nurture, are to analyze a lot of different people who share various amounts of genes and environmental circumstances and then calculate the variance. I’ll use quotes from Judith Rich Harris’ 1995 paper from the “Psychological Review”, Where Is the Child’s Environment? to better explain:

    If heredity can account for only about half of the reliable variation among adults, then environmental influences must account for the rest. The challenge is to find the source of these influences. Behavioral genetic studies have demonstrated which aspects of the environment are not likely to be important. The aspects that are not likely to be important are all those that are shared by children who grow up in the same home: the parents’ personalities and philosophies of child rearing, their presence or absence in the home, the number of books or TV sets or guns the home contains, and so on. In short, almost all of the factors previously associated with the term environment, and associated even more closely with the term nurture, appear to be ineffective in shaping children’s personalities.

    Also, the assumption that children being raised by the same parents, have the same environmental influence is inaccurate, (a) because of temporal difference, (b) because different kids are treated completely differently by parents.

    Maccoby and Martin basically noted this in the early 80′s when they concluded that:

    the implications [of the behavioral genetics, etc. evidence] are either that parental behaviors have no effect, or that the only effective aspects of parenting must vary greatly from one child to another within the same family.

    That micro-environments exist for different children within households is certain, how much effect they have on an individual’s adult outcomes are not. The various reasons that a child might be treated differently by the same parents don’t show much potential in explaining much about one’s adult outcomes. Many things like beauty have such predictable effects on parents and the outside world alike that they end up being part of the nature half of the variance. Again things like birth order, or a siblings age withn a family tell us nothing about long term, or outside the home personalities and life outcomes. This holds true even though a majority of mothers even confess to loving their younger children more – yet no predictable effect on the child’s long term life outcome.

    Also, the assumption that children raised by different parents are subject to fundamentally different environmental influences is also inaccurate. That does not account for the permeating “common culture” of a society.

    Yes, but are very important shared values that affect life outcomes such as the “protestant work ethic” or “German efficiency” or “liberalism” passed from parent to child, or peer-to-peer, or are there over-arching cultural memes affecting both parent and child equally and independently? Or even still are there subtle gene differences between those populations that facilitate or even cause those differences (for instance the two Jewish twins who were raised in Nazi Germany and Latin America respectively shared weirdly specific quarks such as sneezing in elevators and overly-specific fashion aesthetics. Do subtle gene collections result in overly specific cultural patterns within populations?

    If I’m allowed to prophesy, I will say that I expect that there may be some mutations for genius, and some mutations for idiocy in the general gene pool, and only mild influence of genes for the majority of the population around the mean of the IQ distribution.

    I understand IQ to be like height, there aren’t height genes for shortness or tallness. In your version of IQ, to make an analogy, everyone would be about 5’9″, and there would be some problematic cases of people with midget or giant diseases. But it looks like g isn’t like that, at least from what I know (though i think there are IQ anomalies that resemble height anomalies on both ends of the intelligence spectrum), and is actually much more similar to how height works in real life: not a cause of one or two genes, but many; not just based on extremes, but resulting in a some-what smooth bell-shaped gradient of “smarts” around a mean.

  16. Since we ‘re on the subject of IQ , I’ll seize the opportunity to raise a few questions :

    Are IQ 65 africans similar to IQ 65 europeans/north americans/asians ?

    According to the book _IQ and the Wealth of nations_ , the average IQ in Equatorial Guinea is 59 or something like that. Now, i have lived in Africa (right next to EqGuinea in fact) and widely interacted with local people there (i went to school).
    I also have a relative whose IQ was measured to be in the 75-80 range (he lacked oxygen at birth):
    This relative is obviously slow. He will never be truly independent. He probably will never marry. He does earn a living, doing very simple jobs that don’t require much concentration or planning. He’s without malice. Strangely, I can actually have a conversation with him because he does have interests, but he’s basically like a child.
    I simply never got this impression from the majority of the africans i was surrounded with.
    How could have i lived for a decade in a country where the average person is a total moron (IQ 65) without noticing it ? Are there several ways of having such a low IQ ? Are there people whose mental shortcoming are purely in the domain of abstract thought and who otherwise appear totally normal ?

    I sometimes wonder if people like Lynn have ever bothered to even remotely doubt their findings…

    Like most of you on this board, i’m not very impressed by the intellectual output and demeanor of the *average* ghetto dwelling black american. On the other hand, i don’t feel like we’re dealing with people who have no brains whatsoever, do you ?
    I haven’t felt like that either when interacting with africans.

  17. the IQ of 65 or 59 seems totally idiotic. literally :) i suspect we have some flynn effect that will slam it in the next few decades.

    a few points that are suggestive to me.

    the average iqs american blacks is 85. americans blacks are 20% white. the average iqs of west africans is about 70. where did that 15 come from? you could say that selective pressures might have driven the iqs for the two populations in many directions, etc. but the iqs for british blacks is also around 85 (more like 87 or something). coincidence?

    also, another coincidence, the iqs for south asians in the UK is about 95, very close to white average. the iq in india that lynn gives is 81. 15 points. on this though, we can be assured that the indian population in the UK is heterogenous, but skewed toward the higher social classes of the mother country, so this is quite possibly (probably?) a coincidence. the iq of indians in fiji is like 83 btw….

    as for the main point-jensen says in g factor that a black kid with an iq of 70 is not the same as a white with an iq of 70. the white kid is a weird individual-and borderline retarded and probably socially maladept. jensen says that black kids in the 65-70 range have no problem socializing and interacting. muhammed ali had an iq of 71. i think a jewish kid with an iq of 70 would be even weirder….

    also, you are correct that iq tests probably lean toward measuring abstraction abilities and what not. of course, we say that g correlates with a lot of other things, but most of the studies have been done on whites. we don’t know how g correlates in australian aborigines.

    as far as ghetto blacks go, they might not score high on the veral SAT, but they can shoot their mouths like machine guns. similarly, martin luther king was no intellectual very quick-he plagiarized 40% of his Ph.D. thesis. on the other hand, he was a good speaker and rhetoritician (in my judgement).

  18. Are there several ways of having such a low IQ ?

    Ogunsiron,

    There are two main types of retardation in this respect: familial and organic

    organic (pathological retardation) is more often the kind of retardation you think of as a handicap. It comes from harmful genetic conditions (fragile X, down syndrome,etc.), or developmental problems like fetal alcohol syndrome, lack of oxygen at birth, or things like sickness or getting dropped on your head as an infant. Not only do they have low IQ, but have consequent social impairments that make them seem much more different to others than those with familial retardation (who are socially assimilable and can even be charismatic).

    The causes of familial retardation are less clear. It could be the low IQ that results from the environmental conditions of poverty- bad nutrition, non-stimulating environments, lack of intellectual reward, etc., but it could also be the retardation that results from falling on the low end of the natural distribution of human intelligence. Chicken or the egg, b/c low IQ could simply facilitate impoverished conditions, or poverty could breed more poverty, and the condition would be hard to escape from.

    The genetic difference between Africans and African-Americans (or blacks who score similarly in the U.k, Canada, France, Israel, etc.) is not large, so it makes sense that sub-Sarahan Africans probably are for the most part as low as they are b/c of their terrible circumstances.

    The difference between whites and blacks in the U.S regarding retardation is interesting. In 1959 The American Association on Mental Retardation had set the IQ level of retardation at below 85, but this was deemed unacceptable during the Civil Rights era b/c it meant that half of African-Americans were officially classified as retarded. By the 1970′s the level was reduced to below 70 where 12% of blacks were classified as retarded and %2 of whites.

    Almost all whites at IQ levels below 70 are organic cases with readily detected abnormality of function (as are blacks below 55, the cut-off point for the so-called “mid-range” of retardation). The majority of blacks below 70 are like the majority of whites under 85, and would not be socially recognizable as “handicapped”. Their retardation is “familial”, which may be the result of genes or deprivation or both. Statistical models that keep showing up in the psychometric journal Intelligence keep suggesting that it follows recognizable genetic patterns, which makes sense when interpreted next to a body of growing evidence of this nature regarding the b-w difference. But this is a posting for another day…

  19. I don’t think the blank slate theory is any more benevolent than the predetermination theory

    I agree that there is nothing inherently wrong with genenitc causes vs. environmental ones. But Zizka does make the point that, as its played out in America, at least, genetic explanations usually work in the favor of conservative political ideas. (though this isn’t always true. For instance the belief that homosexuality has a genetic component correlates more closely to left-wing politics*.) So, he doesn’t necessarily hear the approach of phantom goose-stepping or anything, but he is aware that there’s political stakes in the issue, so he’ll take it slowly and skeptically.

    Admittedly, where it has affected my politics, geneticism has driven my politics right-ward. Interestingly though in the Snyderman/Rothman survey there was practically no correlation between politics and positions on IQ, including ones on race. The experts surveyed were about 60% Democratic (same as in professional journalism) despite their markedly genetic-leaning responses.

    *but of course, homosexuality does have a genetic component, b/c every trait has a genetic component.

  20. The left is idealistic, and the only reason it has rejected genetic explanations is because genomes are currently immutable.

    Absolutely. I could envision a time when the political roles could even be reversed. The right moves more reluctantly towards science and uncertain change, and GE could lead to all that bull about tampering with God’s creation (same useless stuff that gets injected in stem-cell and cloning debates). Perhaps the left would move towards a position of making GE more and more mandatory to enforce egalitarian goals, with a backlash on the libertarian right. Of course maybe “the right” or “the left” are broad enough that making such generalizations doesn’t work.

    Admittedly, where it has affected my politics, geneticism has driven my politics right-ward.

    On reflection, I don’t know why I said this (perhaps it just seemed intuitively logical); I can’t think of any issue where this has been the case. If all my opinions are considered together I’ve actually probably moved steadily left since high-school, esp. on economic issues but some social ones as well.

  21. There’s lots of evidence that eugenics used to be left. As I remember, Sweden as some skeletons in its closet.

    One problem with the hereditary-racial-dimness theories is that it assumes that there are some environments in which intelligence has no selective advantage. I have trouble even imagining that; intelligence isn’t a niche trait like resistence to malaria or lactose metabolism.

    Lysenko was beyond the pale twice, first as a bad scientist and second (more significantly)as someone who called the secret police on fellow scientists. So I’d like to invoke an adapted version of Godwin’s lw here.

    Those of you who are IQ buffs have probably seen and refuted this already (to your satisfaction) but I have read (no source) that in WWII black Americans from some northern states outperformed white Americans from some southern states.

  22. “*but of course, homosexuality does have a genetic component, b/c every trait has a genetic component.”

    Is this necessarily true? It’s seems clear that homosexuality has a physiological component, but it doesn’t necessarily follow that it has to be encoded in the genome. After all, as Greg Cochran has commented, how could such a gene survive? My own bet is some effect at a critical period in the intrauterine environment (hormones being released or not released at the wrong time) There’s some evidence that later-born boys are more likely to be homosexual – that would seem to argue against a genetic cause…

  23. Jason Malloy wrote:
    The best way to split up and understand the relative contribution of the effects of nurture and nature, and then to further split up the different kinds of nurture, are to analyze a lot of different people who share various amounts of genes and environmental circumstances and then calculate the variance.

    That is my main problem with quantifying the relative effects of nature and nurture [for a related take on this subject: Why Saying that IQ is x% genetic is wrong].

    Current theories do not really quantify the potential of the nurture factor, but rather the effect of the nurture factor in some society.

    Simply put, our range of cultural practices allows for only a certain level of dependence of IQ on culture. While there is a hard limit on genetic potential, there is no hard limit on cultural potential, simply because we have not yet explored the full range of possible cultural practices

    That is why in the nurture/nature debate, I take a position leaning on the nurture side but with a twist: given current nurturing practices, it may be the case that genes have a greater effect. But currently unknown cultural practices may ultimately have the greater effect.

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