# Statistically, blacks score poorly on IQ and IQ-proxy exams than whites, is black genetics to blame? **URL:** \ **Category:** Great Debates\ **Created:** [August 29, 2011, 12:43pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488 "2011-08-29T12:43:51Z")\ **Posts on this page:** 20\ **Page:** 11
**Author:** ![Zoe](https://avatars.discourse-cdn.com/v4/letter/z/a4c791/32.png) [@Zoe](https://boards.straightdope.com/u/Zoe)\ **Post date:** [September 4, 2011, 9:04am UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/201 "2011-09-04T09:04:12Z")
> [@](#): > > **Chen019** : Far more researchers consider than both genetic and environmental variation explains the average IQ difference between US whites & US blacks. Are you speaking of skin color or what some refer to as “races”? I just can’t deal with the later term as a real concept anymore. I’m even shedding my own previous racial label if I can remember to. > [@](#): > > **Really Not All That Bright** : Sure, but that doesn’t tell us anything about slaveowners as a group, which is the assertion that I was responding to. That’s like saying that white Southerners are inherently sociopathic because Southerners have historically treated black people badly. I suppose it’s possible, but hardly the most likely explanation. > [@](#): > > **Boyo Jim** : You must mean it “doesn’t tell us anything about slaveowners as individuals”, because it certainly tells us a lot about them as a group. As a group, they created and supported the escaped slave laws, as a group, they led the South’s secession from the Union, and as a group they created the Jim Crow laws after the war. Does that include the people in New York who had slaves for over 200 years? What about Philadelphia? Some of the New England states? The Southerners were terribly wrong and Jim Crow was more prevalent in the South. But slavery was _generally_ established longer in Northern states. People forget the that part of our history. > [@](#): > > **Chen019** : Whether you call them races, or the more politically acceptable, “major geographic groups” or “major geographic populations” doesn’t change the reality. It isn’t a matter of what is politically correct. It is a matter of what scientists are discovering or have discovered **IS** the reality. Most thinking people want to know when there is a major shift like that. > [@](#): > > **Chen019** : Credence to racial iq theories? What, like Francis Crick & James Watson? I would have been more interested in what Rosalind Franklin would have had to say. ---
**Author:** ![Chen019](https://avatars.discourse-cdn.com/v4/letter/c/f19dbf/32.png) [@Chen019](https://boards.straightdope.com/u/Chen019)\ **Post date:** [September 4, 2011, 9:23am UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/202 "2011-09-04T09:23:22Z")
> [@Zoe](#): > > Are you speaking of skin color or what some refer to as “races”? I just can’t deal with the later term as a real concept anymore. I’m even shedding my own previous racial label if I can remember to. Whether you shed it or not, [self identified ethnicity corresponds almost perfectly to genetic clusters](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1196372/) which reflect geographic ancestry. In the Snyderman Rothman survey they are talking about those in the US particularly. Those are groups that form identifiable clusters. This clustering is a natural consequence of geographical isolation, inheritance and natural selection operating over the last 50k years since humans left Africa. Two groups that form distinct clusters are likely to exhibit different frequency distributions over various genes, leading to average group differences. > [@](#): > > Subjects identified themselves as belonging to one of four major racial/ethnic groups (white, African American, East Asian, and Hispanic) and were recruited from 15 different geographic locales within the United States and Taiwan. Genetic cluster analysis of the microsatellite markers produced four major clusters, which showed near-perfect correspondence with the four self-reported race/ethnicity categories. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [September 4, 2011, 10:22am UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/203 "2011-09-04T10:22:14Z")
> [@Chen019](#): > > Whether you shed it or not, [self identified ethnicity corresponds almost perfectly to genetic clusters](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1196372/) which reflect geographic ancestry. In the Snyderman Rothman survey they are talking about those in the US particularly. Those are groups that form identifiable clusters. > > This clustering is a natural consequence of geographical isolation, inheritance and natural selection operating over the last 50k years since humans left Africa. Two groups that form distinct clusters are likely to exhibit different frequency distributions over various genes, leading to average group differences. This is what I’m hearing from our interlocutors: “Uh, but what is this thing “IQ”? Uh, but what does “difference” really mean? Uh, uh, “African Americans” are just a color. Uh, “the” is a social construct.” Why don’t _we_ just discuss the question? Why do _you_ think that the US gap has a genetic basis? ---
**Author:** ![iiandyiiii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/iiandyiiii/32/7924_2.png) [@iiandyiiii](https://boards.straightdope.com/u/iiandyiiii)\ **Post date:** [September 4, 2011, 1:29pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/204 "2011-09-04T13:29:42Z")
> [@Chen019](#): > > Err, if you read his comments above you’ll see he is asking why those who favour exclusively environmentalist explanations would be opposed to admixture mapping studies of the sort linked to above would resolve the issue of race, genes, and IQ. > > It’s a reasonable question. In reviewing Richard Nisbett’s book, Harvard’s [James Lee](http://www.sciencedirect.com/science/article/pii/S0191886909004097) indeed suggested that would be a way of resolving the issue. > > **Belowjob2.0** , I’m not sure how much of other peoples comments you read, but your view that group differences are exclusively due to environmental factors is very much a minority one. [Far more researchers consider than both genetic and environmental variation explains the average IQ difference between US whites & US blacks](http://en.wikipedia.org/wiki/The_IQ_Controversy,_the_Media_and_Public_Policy_%28book%29). This link you keep posting- there was a single survey, for a book written in 1988, that results in a plurality (46%) saying that genetic variations have something to do with IQ differences. Got anything more recent, or more definitive? ---
**Author:** ![iiandyiiii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/iiandyiiii/32/7924_2.png) [@iiandyiiii](https://boards.straightdope.com/u/iiandyiiii)\ **Post date:** [September 4, 2011, 1:39pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/205 "2011-09-04T13:39:05Z")
If it’s true that there exists WAY more genetic variation among Africans then between Africans and the rest of the world, how can “black” or “African” be considered a legitimate, useful classification when discussing genetics? ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [September 4, 2011, 1:40pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/206 "2011-09-04T13:40:23Z")
> [@Chen019](#): > > Whether you shed it or not, [self identified ethnicity corresponds almost perfectly to genetic clusters](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1196372/) which reflect geographic ancestry. In the Snyderman Rothman survey they are talking about those in the US particularly. Actually, as has been pointed out repeatedly in these discussions, it is not true in the U.S. “particularly,” but in the U.S. almost exclusively. You persistently point to studies of “racial identification” that are based on examinations of the U.S. and other immigrant nations where a founder effect of immigration makes it easier to label people because their ancestors originated from discrete groups from around the world making them easier to identify than an actual examination of the whole of humanity. Blacks in the U.S. originated from a limited section of the West Coast. Chinese arrived from the limited Southeast coastal region. (East) Indians, people from Oceania and other locations in the world are similarly limited in their points of origin and have not been in the U.S. long enough to have any extensive “melting pot” experience. Saying that people “correctly” self identify by “race” in the U.S. is saying nothing more than that we have applied the label “race” to discrete immigrant groups of limited origins. It is meaningless. ---
**Author:** ![iiandyiiii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/iiandyiiii/32/7924_2.png) [@iiandyiiii](https://boards.straightdope.com/u/iiandyiiii)\ **Post date:** [September 4, 2011, 1:44pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/207 "2011-09-04T13:44:48Z")
Chen and Chuck, It may be possible that there are some legitimate, honest researchers who really suspect that racial/genetic variation may have something to do with intelligence. But history shows us that there are far, far more racists who are trying to find a “genetic basis” for their assumptions of black inferiority, and use this type of research as a cover. That’s one reason that your statements are met with such resistance. ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [September 4, 2011, 2:22pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/208 "2011-09-04T14:22:10Z")
> [@iiandyiiii](#): > > If it’s true that there exists WAY more genetic variation among Africans then between Africans and the rest of the world, how can “black” or “African” be considered a legitimate, useful classification when discussing genetics? I would say it would be pretty easy, depending on your criteria are for “legitimate, useful classification.” I imagine that “mammals” might be a legitimate, useful classification for some discussions of genetics even though there is clearly far more genetic variation among mammals than among people as a whole, let alone any subgroup of people. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [September 4, 2011, 9:20pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/209 "2011-09-04T21:20:16Z")
> [@iiandyiiii](#): > > If it’s true that there exists WAY more genetic variation among Africans then between Africans and the rest of the world, how can “black” or “African” be considered a legitimate, useful classification when discussing genetics? Well, admixture studies often deal with specific “African” populations, for example, African Americans, who are primarily of West African descent. [Here](http://www.biomedcentral.com/content/pdf/gb-2009-10-12-r141.pdf) is a PCA of the African-American admixture. Notice that the ancestry clusters. But the nice thing about admixture studies is that, in principle, it doesn’t matter if the groups are hybrids or heterogenous collections – you can look at the specific aggregate ancestries of the groups in question and identify where the phenotype encoding frequencies originated – [Here’s](http://lesacreduprintemps19.files.wordpress.com/2011/09/annurev-genom-082509-141523.pdf) a semi-technical discussion of these studies. (In case you’re wondering, NCSU is my wife’s school, not mine) The problems that you bring up are noted: > [@](#): > > A major challenge in marker selection is ge- netic heterogeneity that may exist among populations contributing to the ancestral parental population—this can be reduced by testing AIMs in several subpopulations and select- ing SNPs that have low information con- tent (e.g., Fst \< 0.05 in pairwise comparisons among North and South American Amerindian populations) (53). In contrast to the rela- tive homogeneity of Europeans and West Africans, Amerindian populations are more genetically diverse (53, 70). It should be noted that admixture maps constructed to date are for admixture mapping in populations where the founding ancestral populations are continental populations—African and European or Amerindian and European. It should also be possible to use admixture mapping for con- tinental subpopulations using the same principles; however, large SNP databases will be required to select SNPs that differentiate be- tween two closely related founder populations since the allele frequency differences are esti- mated to be on average much lower compared to intercontinental [e.g., among African (17, 77) or Amerindian populations (16, 53)] allele- frequency differences. When it comes to disease disparities, average phenotypic differences are identified using national databases (see figure 9). Those that are significantly different are candidates for research. The working idea is that the _aggregate_ phenotypic differences could be a result of _aggregate_ genotypic differences. It seems that people get confused about the last point. They imagine that genotypic differences between populations could only exist if they have a common source or if the populations in question are relatively genetically homogenous. This is not the case. To see this, imagine that we arbitrarily socially constructed two global populations, North Hemispherians and South Hemispherians. These groups would show average phenotypic differences – for example, average differences in skin reflectance. Now, we know that some of the average difference would be due to aggregated genetic differences – even though these two populations represent, from an ancestral genetic perspective, heterogenous + hybrid mixes (e.g. North-Eurasians + North Amerindians, etc versus largely hybrid South Americans + Africans, etc.). (This is why, of course, it’s nonsense to argue that “there can be no genetic differences” because “races are social constructs.”) So back to your question. Yes, “Africans” are a relatively heterogenous population. But 1) often the populations under discussion are not random samples of Africans (e.g. African Americans have mostly West African-African admixture) and 2) even when they are (as would be the case of immigrant “Blacks” in Europe), aggregate genetic differences can still be identified. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [September 4, 2011, 9:58pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/210 "2011-09-04T21:58:12Z")
> [@iiandyiiii](#): > > How can “black” or “African” be considered a legitimate, useful classification when discussing genetics? I guess I don’t understand why some people maintain that population X and Y need to be “(taxonomically?) legitimate, useful classification(s)” in order for there to be identifiable genetic differences. I argue that there are aggregate genotypic IQ, etc. differences between social classes, college populations (e.g. Ivy Leaguers versus Community Collegers), states, ethnic groups, religious groups (e.g. Jews versus Jehovahs witnesses), immigrant group X versus immigrant group y, sexes, arbitrarily constructed groups such as “academically gifted” and “learning disabled,” etc. Basically, given a moderate within group heritability and a plausible mechanism for differentiation (social mobility, selection, evolutionary pressure, SES x membership retention rates, immigration selection, etc), I don’t see any a priori reason for not supposing _average_ genetic differences. And I’m not unique among hereditarian thinking people. For example, M & H spend 9/10ths of The Bell Curve dealing with geneotypic differences between social classes, which are about as “socially constructed” as you can get – and, of course, the major criticism of the book was that “races are social constructs.” ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [September 4, 2011, 10:01pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/211 "2011-09-04T22:01:53Z")
> [@iiandyiiii](#): > > This link you keep posting- there was a single survey, for a book written in 1988, that results in a plurality (46%) saying that genetic variations have something to do with IQ differences. > > Got anything more recent, or more definitive? No, that was the only survey done. ---
**Author:** ![iiandyiiii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/iiandyiiii/32/7924_2.png) [@iiandyiiii](https://boards.straightdope.com/u/iiandyiiii)\ **Post date:** [September 4, 2011, 10:32pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/212 "2011-09-04T22:32:09Z")
> [@Chuck11](#): > > No, that was the only survey done. Then the point has awfully weak support. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [September 4, 2011, 10:52pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/213 "2011-09-04T22:52:58Z")
> [@iiandyiiii](#): > > Chen and Chuck, > > But history shows us that there are far, far more racists who are trying to find a “genetic basis” for their assumptions of black inferiority, and use this type of research as a cover. What proof do you have of this? In your opinion, “racists” are an irrational bunch that attempt to use genetics to construct narratives to keep “others” down. You’re toting the marxist line. I’m sure that you can cite all sorts of clever psychoanalyses that expound this, but what evidence do you have that these analysis, these intellectual stances, are correct? Why are you supposing that “racists” are motivated by the desire to believe in black inferiority? Why not suppose that “racist” conclude that blacks are inferior based on the preponderance of the evidence? It seems to me that “anti-racists” are bent in believing that “racists” are bent in believing that blacks are inferior, so that you don’t have to debate them or provide evidence to the contrary. The problems that I have is that “anti-racists” inevitably accuse me of racism for “keeping the black man down.” When I say nothing, they take this as an admission of guilt. When I try to point out alternative explanations, cultural or genetic, for some of the “disparities,” I am accused of “just hating black people.” When I try to explain why I do what I do, I’m accused of rationalizing my supposed hatred and so on. So I don’t bother trying to show that I’m not “racist”; in fact, I’ve come to think that this thing called “racism” probably isn’t that bad after all. What I do now is simply demand proof that “blacks” are not “inferior” (i.e. that the statistical average differences commonly said to be the product of my racism is not, in fact, a product of aggregate genetic differences) and make my case that the difference could reasonably be due to genetics. ---
**Author:** ![iiandyiiii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/iiandyiiii/32/7924_2.png) [@iiandyiiii](https://boards.straightdope.com/u/iiandyiiii)\ **Post date:** [September 4, 2011, 11:04pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/214 "2011-09-04T23:04:57Z")
> [@Chuck11](#): > > What proof do you have of this? In your opinion, “racists” are an irrational bunch that attempt to use genetics to construct narratives to keep “others” down. You’re toting the marxist line. I’m sure that you can cite all sorts of clever psychoanalyses that expound this, but what evidence do you have that these analysis, these intellectual stances, are correct? Why are you supposing that “racists” are motivated by the desire to believe in black inferiority? Why not suppose that “racist” conclude that blacks are inferior based on the preponderance of the evidence? It seems to me that “anti-racists” are bent in believing that “racists” are bent in believing that blacks are inferior, so that you don’t have to debate them or provide evidence to the contrary. > > The problems that I have is that “anti-racists” inevitably accuse me of racism for “keeping the black man down.” When I say nothing, they take this as an admission of guilt. When I try to point out alternative explanations, cultural or genetic, for some of the “disparities,” I am accused of “just hating black people.” When I try to explain why I do what I do, I’m accused of rationalizing my supposed hatred and so on. So I don’t bother trying to show that I’m not “racist”; in fact, I’ve come to think that this thing called “racism” probably isn’t that bad after all. What I do now is simply demand proof that “blacks” are not “inferior” (i.e. that the statistical average differences commonly said to be the product of my racism is not, in fact, a product of aggregate genetic differences) and make my case that the difference could reasonably be due to genetics. I understand better now, thank you. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [September 4, 2011, 11:09pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/215 "2011-09-04T23:09:31Z")
> [@iiandyiiii](#): > > Then the point has awfully weak support. The point is just to establish the plausibility of a genetic hypothesis and so to bolster the case for [testing](http://www.nature.com/nature/journal/v457/n7231/full/457788a.html) it. For this, only weak support should be needed. ---
**Author:** ![Belowjob2.0](https://avatars.discourse-cdn.com/v4/letter/b/b9e5f3/32.png) [@Belowjob2.0](https://boards.straightdope.com/u/Belowjob2.0)\ **Post date:** [September 4, 2011, 11:20pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/216 "2011-09-04T23:20:17Z")
> [@Chuck11](#): > > I guess I don’t understand why some people maintain that population X and Y need to be “(taxonomically?) legitimate, useful classification(s)” in order for there to be identifiable genetic differences. I argue that there are aggregate genotypic IQ, etc. differences between social classes, college populations (e.g. Ivy Leaguers versus Community Collegers), states, ethnic groups, religious groups (e.g. Jews versus Jehovahs witnesses), immigrant group X versus immigrant group y, sexes, arbitrarily constructed groups such as “academically gifted” and “learning disabled,” etc. Basically, given a moderate within group heritability and a plausible mechanism for differentiation (social mobility, selection, evolutionary pressure, SES x membership retention rates, immigration selection, etc), I don’t see any a priori reason for not supposing _average_ genetic differences. And I’m not unique among hereditarian thinking people. For example, M & H spend 9/10ths of The Bell Curve dealing with geneotypic differences between social classes, which are about as “socially constructed” as you can get – and, of course, the major criticism of the book was that “races are social constructs.” Because your boy Chen19 has repeatedly made claims about global “black populations”. Do you now acknowledge that any such claims are invalid, and that the field of inquiry has to restricted to black Americans only? Do you also acknowledge that your cabal’s claims about African intelligence depend heavily on the work of Richard Lynn, who’s a proven fraud? ---
**Author:** ![brazil84](https://avatars.discourse-cdn.com/v4/letter/b/8491ac/32.png) [@brazil84](https://boards.straightdope.com/u/brazil84)\ **Post date:** [September 5, 2011, 1:02am UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/217 "2011-09-05T01:02:33Z")
> [@Chuck11](#): > > I guess I don’t understand why some people maintain that population X and Y need to be “(taxonomically?) legitimate, useful classification(s)” in order for there to be identifiable genetic differences. I agree that this does not make a lot of logical sense. It’s easy enough to think of classification systems for humans which are completely arbitrary and artificial; with classes that are significantly different in some measurable characteristic; and the difference is clearly the result of genetics. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [September 5, 2011, 1:09am UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/218 "2011-09-05T01:09:45Z")
> [@Belowjob2.0](#): > > Because your boy Chen19 has repeatedly made claims about global “black populations”. Do you now acknowledge that any such claims are invalid, and that the field of inquiry has to restricted to black Americans only? I’m not sure what you’re saying. I generally restrict my claims to African Americans for three reasons: 1) For what I’m interested in, in this instance, I don’t need to talk about global blacks; for all I know, the African admixture in African-Americans comes from an unrepresentative sample of a larger African and West African population. Let me quote the noted psychologists Hans Eysenck on this: “Thus there is every reason to expect that the particular sub-sample of the negro race which is constituted of American Negroes is not an unselected sample of Negroes, but has been selected throughout history according to criteria which would put the highly intelligent at a disadvantage. The inevitable outcome of such selection would of course be the creation of a gene pool lacking some of the genes making for high intelligence.” Maybe this is improbable, I don’t know. 2) Most statistical analyses of IQ differences have concerned African and European Americans. These include numerous tests of measurement bias, reliability, and predictive validity. Several multigroup confirmative factor analysis have been done and have shown that the between Black-White difference is of the same nature as the within Black and within White difference (i.e. is a real IQ difference), implying that it is caused by a subset of the within differences (environmental or genetic). Together, these rule out measurement bias as an explanation, or at least substantial explanation, for the gap and severally constrain environmental explanations. Little of this can be said for global differences. We don’t even know how heritable IQ is in Africa. What we know is that the differences are scores difference which behave like real IQ differences. They might, in fact, be true IQ differences and therefore they might might be due to genetics. 3) The direct evidence for a global genetic hypothesis is much weaker than that for an American genetic hypothesis (which includes regression to the mean studies, structural equation modeling studies, 3 nationally representative studies showing the predicted mixed race difference, \>12 (weakly) supporting (but \> 3 contrary) admixture studies, 1 supporting (but 1 contrary) adoption study, etc.) Basically, I feel that I can make a strong genetic case for the US differences but not global differences. That said, I wouldn’t maintain that global genetic differences are implausible. And as I noted above, these differences could be genetic via convergent evolution even if Black Africans are not very homogenous. After all, all Black African populations, regardless of their genetic relationship, tend to be Black and presumably for partial genetic reasons. > [@](#): > > Do you also acknowledge that your cabal’s claims about African intelligence depend heavily on the work of Richard Lynn, who’s a proven fraud? Whatcha talkin’ about Willis? I already commented on this. Let’s hear your particular criticism. The validity of Lynn’s IQs, at least on the national level, have been largely confirmed. The question about them is: Are they like the Within population difference/between US Black-White difference? That is: does strong measurement invariance hold between the cross national differences? ---
**Author:** ![Chen019](https://avatars.discourse-cdn.com/v4/letter/c/f19dbf/32.png) [@Chen019](https://boards.straightdope.com/u/Chen019)\ **Post date:** [September 5, 2011, 8:45am UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/219 "2011-09-05T08:45:55Z")
> [@iiandyiiii](#): > > This link you keep posting- there was a single survey, for a book written in 1988, that results in a plurality (46%) saying that genetic variations have something to do with IQ differences. > > Got anything more recent, or more definitive? The reason I refer to the [Snyderman & Rothman](http://en.wikipedia.org/wiki/The_IQ_Controversy,_the_Media_and_Public_Policy_%28book%29) survey is because there seems to be an assumption that there is a consensus that group differences are entirely due to environmental factors. In fact, that explanation appears to have far less support than the explanation that they are the product of genetic **and** environmental variation. It is also an interesting example of how an issue can be poorly reported (I’d recommend reading the book itself). If you want a more up to date discussion of the evidence the [June 2005 issue of Psychology, Public Policy, and Law](http://www.udel.edu/educ/gottfredson/30years/) is a good place to start. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [September 5, 2011, 9:31am UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/220 "2011-09-05T09:31:42Z")
> [@Chen019](#): > > The reason I refer to the [Snyderman & Rothman](http://en.wikipedia.org/wiki/The_IQ_Controversy,_the_Media_and_Public_Policy_%28book%29) survey is because there seems to be an assumption that there is a consensus that group differences are entirely due to environmental factors. In fact, that explanation appears to have far less support than the explanation that they are the product of genetic **and** environmental variation. > > It is also an interesting example of how an issue can be poorly reported (I’d recommend reading the book itself). We had this conversation before, [http://boardstest.straightdope.com/sdmb/showpost.php?p=13693853&postcount=501](http://boardstest.straightdope.com/sdmb/showpost.php?p=13693853&postcount=501) The survey did not include anthropologists or biologists, and few geneticists. Whoever did this survey is playing loose and fast with what an expert in the matter is, as it was in reality a grab bag of diverse fields that they surveyed. This is using a similar tactic as the survey the global warming deniers did showing that 32000 “experts” do not see that humans are causing the current warming that is being observed: [http://climatecrocks.com/2010/01/09/32000-scientists/](http://climatecrocks.com/2010/01/09/32000-scientists/) What they did was to avoid surveying the experts that count so as to get the results they wanted. A worthless survey. [Previous page](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488.md?page=10) [Next page](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488.md?page=12)