Genetic and Environmental Causes of Human Diversity

Just because a side in an argument uses bad arguments doesn’t mean it’s wrong. By far, the least logic and most emotional rhetoric I have ever seen was in the newsgroup talk.origins in the late 1990s, where evolutionists were bufeddled and angered by the repleis of the creationists. That doesn’t mean that descent with modification by natural selection is a wrong theory. It means that the truth was weaker in its rhetoric than the false.

With that said, Stephen Metcalf’s “Dissecting the IQ Debate: A Response to William Saletan’s Series on Race and IQ” (hat-tip to The Corner and South Dakota Politics) is awful.

After a lengthy ad hominem attack, Metcalf begins addressing evidence for racial differences in IQ.

First:

Much of Saletan’s précis of the rest of the research surveyed in “Thirty Years of Research Into Race Differences on Cognitive Abilities” is highly questionable. His takeaway regarding the “admixture” studies is precisely the opposite of what an American Psychological Association task force concluded the studies show—that more “European” blood in a black American does not make him smarter.

Pay attention here. Metcalf attacks Saletan for citing a peer-reviewed journal article, when a politically selected task force disagreed with its conclusions. No one denies the factual claims of the article: that European admixture positively correlates with general intelligence among African-Americans. Indeed, that alone is not evidence of innate racial differences. But the correlation between miscegenation and g in the population does not go away even when corrected for other variables.

Second:

Saletan points up the problems with a favorite study of the environmentalists, into the IQ outcomes of children fathered by foreign soldiers and raised by (white) German mothers. This study showed that kids with African fathers scored the same as those with white fathers. But, Saletan says, it suffers from a fatal flaw: Blacks in the military had been screened for IQ. Saletan concludes, “Even environmentalists (scholars who advocate nongenetic explanations) concede that this filter radically distorted the numbers.” But this is flatly untrue. The two most prominent environmentalists, Richard Nisbett and James Flynn, have dismissed this very objection. Both have pointed out that white soldiers were also screened, and so had higher IQs than the general white population.

This regards a study that finds Germans with African-American fathers have an IQ about that of the German population. This might be explained by the fact that the military screens for IQ, rejecting a disproportionately high number of African-Americans for that reason. The counter-argument that European-Americans were also screened is besides the point: the US Army in WWII did not engage in affirmative action. The minimum IQ level for blacks was the same as the minimum IQ level for whites.

Third:


Saletan uses a sheer volume of statistics to create an aura of gathering unanimity, but many of his statistics have been taken at face value. To take one example: Saletan casually countenances the assertion that the mean IQ of sub-Saharan Africa is 70. The number arrives to us via a man named Richard Lynn. Lynn is the author of the 1996 volume “Dysgenics: Genetic Deterioration in Modern Populations.” In “historical societies,” Lynn wrote, “illegitimate children, born predominantly to parents with low intelligence and weak character, suffered high mortality.” Until the scourge of modern medicine, such culling assured the expulsion of weaklings from the gene pool, while the “operation of positive natural selection” ensured the “reproductive fitness of the leaders and of the upper and middle classes.” The instrument Lynn used to apprehend these depressed IQ scores is a supposedly culturally unbiased exam called Raven’s Progressive Matrices. “To use an instrument developed in the West on semi and possibly illiterate people is a fool’s errand,” says Nisbett, a Distinguished University Professor at the University of Michigan who studies cognition and social psychology. “Then they use the results to say that half the people in Africa are mentally retarded. It’s laughable.”

Here, the web can help out. The table in Flynn’s book is available online. Some tests use the Raven tool, others use other tool.

The next paragraph again relies on the political summary of an APA body, and thus is unoworthy of comment.

Next:

Furthermore, the APA task force lays out—finally!—the real heart of the conflict. To understand what is really being fought over when we fight over the IQ gap between blacks and whites, its authors explain, you must think through an analogy. Imagine two wheat fields. Now imagine two genetically identical sets of seeds. (The analogy was first made famous by the Harvard evolutionary biologist and geneticist Richard Lewontin.) Now imagine each field is planted with these two identical seed stocks. Field No. 1 is given the best possible inputs: sunshine intensity, rain, soil nitrates, etc. Field No. 2 is given much less of all of the above. Within each field, inputs are kept uniform. Inevitably, the first field grows a healthier supply of grain than the second. But here is the rub: Within each field, the variation in outcomes is entirely hereditary. Between the two fields, the variation in outcomes in entirely environmental.

An excellent analogy. Using it, one would expect that environment differences, such as parent’s income, drown out genetic differences, such as race.

But that is just not so. From the original Saletan article:

My first reaction, looking at this pattern, was that if the highest-scoring blacks are those who have lighter skin or live in whiter countries, the reason must be their high socioeconomic status relative to other blacks. But then you have to explain why, on the SAT, white kids from households with annual incomes of $20,000 to $30,000 easily outscore black kids from households with annual incomes of $80,000 to $100,000. You also have to explain why, on IQ tests, white kids of parents with low incomes ­and low IQs outscore black kids of parents with high incomes and high IQs. Or why Inuits and Native Americans outscore American blacks.

But Metcalf makes it clear that he believes that living in a good neighborhood, in a good home, with high-income parents, it itself drowned out by “the legacy of American racism.”

In the absence of some startling new evidence, the crux of the issue turns out to be this: Do you believe the legacy of American racism, in all its complexity, can explain depressed black IQ scores, even when controlling for all other factors, including socioeconomic status? Is the black experience, in other words, so unique as to constitute, for nearly all black Americans, a separate wheat field? If you say yes, then good news: You believe (along with the most prominent environmentalists) that the black-white IQ gap will close in the next 50 or so years. If you think no, then bad news: You believe, with the most prominent hereditarians, that blacks as a group must resign themselves to higher rates of poverty, unemployment, divorce, and violent criminality purely as a matter of genetic fate.

Indeed. This is the first good point that Metcalf makes in the entire article.

Such a “legacy of racism” must be indirect, as it does not seem to harm either Afro-Carribeans or immigrants from Africa.

More likely, such a legacy of racism is the profoundly broken African-American culture. This, and not “racism” as its commonly conceived, is the explanation that James Flynn and other environmentalists look for. And perhaps they are right.

But there is another explanation: as immigrant populations, both Afro-Carribeans and immigrants from Africa are self-selected: moving to a new country is dangerous, especially when it means weakening the strong family ties back home. It requires a special something — a something that can include general intelligence — to go through the time-consuming and dangerous immigration process. Perhaps the reason that black immigrants from Africa and the Carribean do better than African Americans on so many measures is precisely genetic.

15 thoughts on “Genetic and Environmental Causes of Human Diversity”

  1. What I wonder is why people care whether it's hereditary or not? If the environmentalists are correct, certain actions by society should eliminate the gap between races over the course of a few generations. If the hereditarians are correct, those same actions by society might STILL be good ideas– by reducing the number of factors pushing black people into poverty, fewer will be poor.

    A better debate would be on what measure would actually work best to reduce the environmental pressures on African-Americans.

  2. J,

    “On a previous comment you suggested that using experts in a field was a cop out appealing to a higher authority, ignoring that authority equals decades of experience and peer review. However, in this post you yourself relied upon people that you tout as experts in the field.”

    I was unaware I did this. Could you point out where I made my mistake, so I could fix it?

    “Maybe in the future (regarding a previous thread) you should refrain from using Wikipedia as a source.

    A fair criticism. Wikipedia is a good second source, but obviously is not a proper primary source. Regarding the specific claims I made in the other thread [1], both Lewontin's fallacy [2] and the haplogroup claims [3] are available online.

    Michael,

    “True, but some of the studies Saletan cited did show improvements based on improvements to the environment. As studies of the environment's effects reveal what works, that data can be turned into plans to give more children that environment.”

    Very good. A famous example of this is early Chinese-American IQ in the US seemed to be below average, where now the situation is reversed. Other immigrant groups have made similar gains.

    It strikes me that in order to believe that the same thing is going on because of the “legacy of racism,” one has to believe that the living conditions of a black child in a high SES family are roughly equivelent to growing up in third-world conditions. Maybe — I believe that Flynn does think that African-Americna culture is that bad — but it seems a stretch.

    “Think about it this way. What better way to challenge the hard-core environmental idealogues than to deal with the subject on their own terms? If they want to argue that race-based affirmative action works, fine, let them present their evidence. You'll present your evidence that it doesn't work and that other changes work better. As that debate is settled, and more hard data comes in regarding genetic issues, the genetics debate will become easier to have.”

    Indeed.

    Unfortunately, like the anti-scientists on the right, the public face of the debate is controlled by naive politicos. Take Head Start, for instance. The evidence is overwhelming that it does not work. Gains are made for a few years and then rapidly lost. The heridtarian answer is that peer socialization, etc., is so important, unless a very large fraction of the population goes through head start it can't work for anyone. A more biological explanation is that head start produces an artificial increase in g at a time when g is most open to temporary manipulations. Yet the program is still adored by Democratic activists in the same way that abstinence-only education is adored by Republican activists.

    “Non-rhetorical question: how do you know that APA task forces are politically created?”

    The American Psychological Association (I'm not a member, but that's out of cheapness — I probably should join) is a roughly democratic professional/academic association. The APA hosts a huge yearly annual convention, plus smaller local and specialized meetings throughout the world. The APA divides itself into specialities, such as cognitive psychological, educational psychology, etc., with their own journals and other activities. It's pretty well run

    An excellent overview of the APA's governing structure is available from the APA itself. [4] Essentially, the membership elects a Council of Representatives. The Concil selects a Board of Directors. “Task forces” are then created by the Board of Representatives.

    [1] http://www.tdaxp.com/archive/2007/12/02/a-pagan-intuition.html
    [2] http://www.goodrumj.com/Edwards.pdf
    [3] http://www.le.ac.uk/genetics/maj4/JoblingTS.03.NRG.Review.pdf
    [4] http://www.apa.org/about/structure.html

  3. It is clear that despite overwhelming scientific and anthropological evidence you think that your interpretation is somehow more qualified than experts in the field.

    On a previous comment you suggested that using experts in a field was a cop out appealing to a higher authority, ignoring that authority equals decades of experience and peer review. However, in this post you yourself relied upon people that you tout as experts in the field.

    This quasi-racism in the face of scientific facts is appauling. Before you say that this is an unfair ad hominem attack – duh.

    …Maybe in the future (regarding a previous thread) you should refrain from using Wikipedia as a source.

  4. “If genes do matter here, however, outcomes may become more unequal as environments equalize. “

    True, but some of the studies Saletan cited did show improvements based on improvements to the environment. As studies of the environment's effects reveal what works, that data can be turned into plans to give more children that environment.

    Think about it this way. What better way to challenge the hard-core environmental idealogues than to deal with the subject on their own terms? If they want to argue that race-based affirmative action works, fine, let them present their evidence. You'll present your evidence that it doesn't work and that other changes work better. As that debate is settled, and more hard data comes in regarding genetic issues, the genetics debate will become easier to have.

    Non-rhetorical question: how do you know that APA task forces are politically created?

  5. Michael,

    “What I wonder is why people care whether it's hereditary or not? If the environmentalists are correct, certain actions by society should eliminate the gap between races over the course of a few generations.”

    Knowledge of DNA's component for group difference lets us guess what will happen if the government attempts to equalize environments between the races. If heredity plays no role in group differences, then equal environments should generate equal outcomes. If genes do matter here, however, outcomes may become more unequal as environments equalize.

    “If the hereditarians are correct, those same actions by society might STILL be good ideas– by reducing the number of factors pushing black people into poverty, fewer will be poor.”

    They might, or they might not.

    If IQ is a function of SES (which some campus marxist-types believe), then affirmative action is a relatively straight-forward way of equalizing general intelligence between the races: there may be some injustice in the short run, but a generation later you will hae a black technocratic class that is self-sustaining.

    If, however, black children of high SES parents do less well on intelligence tests than white children of low SES parents, affirmative action is not serving the goal of creating a black technocratic class.

  6. Regarding your A Pagan Institution piece….

    “I won't comment on Franz Boas' personal beliefs. Logically, of course, an argument to authority is a logical fallacy.”

  7. J,

    I think I was unclear. I apologize.

    I recognize that citing Boas words as authoritative is a logical fallacy. I stand by that.

    Did I make a similar fallacy in my comment? That is, did I cite an “authority” rather than evidence for some claim?

  8. Throughout your post you mention Saletan, Richard Nisbett, James Flynn, and the APA. You don't thoroughly cite thier evidence. You just reference their conclusions – the same thing that I did. There is no difference between me referencing the conclusions of Boas and you referencing the conclusions of others. Throughout your post you merely say that X disagrees with Y because of Z. That's not evidence, that's you saying that someone's conclusion overwrites another's because for some magical reason his opinion matters more. If you actually presented all of the statistics behind their conclusions and analyzed it step by step then that would be you presenting evidence.
    But currently you just reference conclusions based off of unsubstantiated results and act as if because the conclusions are followed up by generalization of results that that serves as evidence that is somehow superior to me generalizing conclusions without excerpts from articles is somehow different.
    Excerpts from articles that reference conclusions does not make your argument more legitimate than my arguments. Just because I didn't link wikipedia to conclusions drawn by Boas doesn't mean that his assertions were wrong or less valid.

  9. Here are two pieces of substantive evidence which points to the existence of biological races.

    In the first, a genetic clustering analysis correctly predicts self-described race, with an error rate of something between 1 and 10 in 1,00. [1]

    In the second, the degree to which races are under different selection pressure is described. [2]

    Do you want more? 10 articles? 20? Does the weight of this evidence not matter, because you are looking for something different? (For instance, do you disagree with the principles behind clustering analysis, or… ? )

    [1] http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1196372
    [2] http://biology.plosjournals.org/perlserv?request=get-document&doi=10.1371/journal.pbio.0040072

  10. My point that you were using the same ad fallacy as before still stands undefended?

    I never said that there weren't variations between groups – so what are you trying to prove to me?

    I have said that races are predominately a culture creation, but I also said that there were distinct variations. Your evidence doesn't counter my thoughts, rather it agrees with them.

  11. J,

    You indicated my rhetoric was not substantive, so in response I provided you with more substantive sources for my claim. There is no reason or point for me to say “was not!,” when it's just as easy and much more useful to take your criticisms in good faith, and use that opportunity to improve my presentation.

    “I never said that there weren't variations between groups – so what are you trying to prove to me?”

    Earlier, in the comments, you said

    “I understand that genetics clearly show ancestory but the point is that race is not a real category. There is no biological evidence that clearly defines a race.” [1]

    My point, in part is that race is a real category, biological evidence describes what races are, etc.

    “Your evidence doesn't counter my thoughts, rather it agrees with them.”

    Could you outline your thoughts for me again, so I know what evidence to provide you?

    [1] http://www.tdaxp.com/archive/2007/12/02/a-pagan-intuition.html

  12. I just think it's funny that you can attack someone's type of argument and then you used one yourself – I'm glad you corrected yourself though.

    My thoughts included the idea that there are distinct variations that can be associated with a particular group of people, however, they are not distinct enough to account for people belonging to different races that indicate any substantial degree of difference in a way that can imply the idea of subspecies or allow for claims that one race is inferior to another – essentially making claims that one race has an inferior intellect is not a biologically sound claim.

    My biological evidence from Boas, and Miller, mentioned in earlier threads, clearly shows my thoughts and the scientific communities' thoughts. Does the weight of that evidence not matter?
    I think that it should have some weight when the leaders of the scientific community (not necessarily the people I listed) are as a whole disgusted at the notion that race has any substantive basis for claims of inferiority, lower quality of intellect, or less skills.

  13. J,

    “My thoughts included the idea that there are distinct variations that can be associated with a particular group of people, however, they are not distinct enough to account for people belonging to different races that indicate any substantial degree of difference in a way that can imply the idea of subspecies”

    Agreed that there are no extant subspecies among homo sapiens.

    “or allow for claims that one race is inferior to another”

    Not sure what you mean by “inferior.”

    If you mean it in a moral or normative sense, then it's not a scientific question.

    If you mean in a quantitative trait sense, then clearly such differences exist. The skin color of northern Europeans is “inferior” wrt life expectency near the equator. The reverse is true of those with dark skins farther away from the equator. But why you would want to use such a loaded work like “inferior” when “different in a way that affects life-outcomes” is more neutral is beyond me.

    If you mean in a psychometric trait sense…. then it's an open scientific question. Certainly there could be such variation, there is evidence for it, and the variation wrt IQ does not go away when you adjust for other factors. But then again, our knowledge is limited, and perhaps what we “know” will change in the next 20 years.

    ” – essentially making claims that one race has an inferior intellect is not a biologically sound claim.”

    Not sure what you mean by “sound” here. If you mean “proven,” then of course not. If you mean “valid,” then of course yet.

    “My biological evidence from Boas, and Miller, mentioned in earlier threads, clearly shows my thoughts and the scientific communities' thoughts. Does the weight of that evidence not matter?”

    You cited a quotation by Barbara Miller, not evidence that she presented.
    You cited a claim by Franz Boas, who died 65 years ago.

    The “weight” of the evidence you presented is very little, indeed, as all you hae presented is a quote without supporting evidence and the belief of a great man who died before DNA was discovered.

    “I think that it should have some weight when the leaders of the scientific community (not necessarily the people I listed) are as a whole disgusted at the notion that race has any substantive basis for claims of inferiority, lower quality of intellect, or less skills.”

    I wonder if this is a fundemental difference in our views of science.

    I look toward scientific evidence, and draw conclusions from that.
    Perhaps it is that you look toward the feelings that scientific claims arouse in people, and draw your conclusions from those?

  14. Did you admit that science hasn't “proven” your theories? If so, then it is clearly you who does not draw conclusions from scientific evidence. You seem to be relying upon people that make claims that you emotionally feel as sound and then latch on to them despite the scientific community as a whole rejecting them. Your evidence doesn't mention that intellect is a factor of race, rather it embraces my claim that there are some variations within a race – but, those variations regard geographics rather than any substantial differnces. Essentially, if Europeans lived in Africa for hundreds of thousands of years they would be more African because their bodies would adapt. That wouldn't make them less intellectually capable, it just means that there is a difference because of human response to environment.

    In regards to using little weight – I thought that since you didn't bother to discount your original post which relied upon conclusions of scientists rather than examining evidence meant that you accepted my use of conclusions as valid. If not, then you should disavow your original post and rely only upon your recent comments.

    I find your critique of the word inferior to be laughable. You yourself defined cultures as inferior in an earlier thread. You said we should destroy inferior cultures. I thought it was acceptable to use the word inferior to a person who uses the word so frequently.
    I think it's pretty clear what inferior means when you continue to read my post, it includes the notion of having less intellect and less skill.

    And once again,
    I think that it should have some weight when the leaders of the scientific community (not necessarily the people I listed) are as a whole disgusted at the notion that race has any substantive basis for claims of inferiority, lower quality of intellect, or less skills.

  15. “Did you admit that science hasn't “proven” your theories?”

    Of course, because science does not prove theories. Hence the “evolution is only a theory” rubbish you hear from time to time — of course it is.

    “If so, then it is clearly you who does not draw conclusions from scientific evidence.”

    That doesn't follow.

    It is important to realize that the ability of race to predict general intelligence does not wash out when you correct for other variables. For example, the children of high-income african-american parents score worse on general intelligence tests than the children of low-income european-american parents. If IQ really was just a proxy for social class, or something similar, you should not see this effect.

    Do you want evidence for this? If so, what kind? (I would naturally think that journal articles would get the point across best, but perhaps you would like something else?)

    “Your evidence doesn't mention that intellect is a factor of race, rather it embraces my claim that there are some variations within a race – but, those variations regard geographics rather than any substantial differnces. Essentially, if Europeans lived in Africa for hundreds of thousands of years they would be more African because their bodies would adapt. That wouldn't make them less intellectually capable, it just means that there is a difference because of human response to environment.”

    I'm not sure what you mean by “geography”? Of course natural selection operates in the geographical area that animals exist in. And of course this can lead to substantial changes. For instance, there is evidence that the intelligence of Jews [1] and a host of genes [2] are under recent selection, and this of course is a result of geography, among other factors.

    “In regards to using little weight – I thought that since you didn't bother to discount your original post which relied upon conclusions of scientists rather than examining evidence meant that you accepted my use of conclusions as valid. If not, then you should disavow your original post and rely only upon your recent comments.”

    If you do not believe that a blog post that gives context for a discussion provides substantive evidence as to who in the discussion is correct, then you are free to ignore it.

    When you have criticized me for not providing evidence, I have provided it.

    But I have noted many times you have not proided evidence. Still you do not.

    I provide you both with summaries of articles and the articles themselves.

    But you provide me with 50-year-old beliefs, one quote from a press release, and an impression of disgust.

    “I find your critique of the word inferior to be laughable. You yourself defined cultures as inferior in an earlier thread. You said we should destroy inferior cultures. I thought it was acceptable to use the word inferior to a person who uses the word so frequently.”

    Humans are persons. Cultures are objects.

    All persons are equally morally valuable. But of course, some cultures are better than others. A person is an end-in-himself, but a culture is merely a means to providing persons with their rights, good lives, etc.

    “And once again,
    I think that it should have some weight when the leaders of the scientific community (not necessarily the people I listed) are as a whole disgusted at the notion that race has any substantive basis for claims of inferiority, lower quality of intellect, or less skills.”

    Because you are repeating your point, let me repeat my question.

    Woudl you agree that the difference in our views of science is that you draw your conclusion on the validity of from the emotions that scientific evidences arouse in people (such as disgust, etc.) while I draw my conclusions from the
    evidence itself?

    [1] http://harpending.utah.edu/Documents/ashkiq.webpub.pdf
    [2] http://www.pnas.org/cgi/content/abstract/103/1/135

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