# Race differences in average IQ are largely genetic **URL:** \ **Category:** Great Debates\ **Created:** [May 27, 2012, 12:28pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236 "2012-05-27T12:28:24Z")\ **Posts on this page:** 20\ **Page:** 34
**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:** [June 21, 2012, 7:00pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/661 "2012-06-21T19:00:49Z")
> [@Chuck11](#): > > The good news for race realists is that they can now readily dismiss all the arguments to the effect that there are too few genetic differences between races or that there was too little time to evolve them! I’m repeating myself, but I remain unconvinced of the genetic difference between the races. While it is not a complete genome, the mitochondrial DNA-based phylogenetic tree shows many sub-Saharan African populations that are closer to Eurasians than to many other African populations. The analysis by Witherspoon and others implies that, > [@](#): > > when enough loci are considered, individuals from these population groups will always be genetically most similar to members of their own group. but they’re referring to populations, not races. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [June 21, 2012, 7:23pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/662 "2012-06-21T19:23:23Z")
> [@PBear42](#): > > [hijack] > > If this has been mentioned, I missed it. The fundamental flaw in the OP isn’t whether it’s true. Intelligence may well be partly genetic and, at least in part, may be sorted by race (however defined). So what? Let’s assume the ability to play basketball is similarly sorted by race (however defined). Does this mean all blacks (or whatever) who try out make the team? Does it mean that no whites (or whatever) do not? In both cases, no. Rather, we give 'em the ball and see how well they play. So, too, with intelligence and any other aspect of vocational competence we care to consider. What matters isn’t what group or race to which you belong. What matters is how well you play the game. > > I doubt anyone participating in the thread disagrees. > > [/hijack] I disagree – The OP is in clear agreement with the statement about treating individuals as individuals. Quote: > [@](#): > > It is a widely accepted fact of behavioral science that there is great variability within each racial group and there is an ethical consensus that we treat people as individuals. Although no specific policies necessarily follow from knowing about the causes of group differences, they may serve as guides to action on som issues. The conclusion reached in Sections 13 and 14—that about 50% of the variance in mean Black–White group differences in IQ is due to heredity—is compatible with a wide range of recommendations, from programs for the disadvantaged and laissez-faire approaches to selection and opportunity grouping in certain educational and vocational situations. > > In The Bell Curve, Herrnstein and Murray (1994) offered some specific policy recommendations based on their conclusions about genetic variation and IQ, which are generally concordant with political conservatism, such as scaling back affirmative action, reducing the intrusiveness of government, and returning to individualism. Most political conservatives, however, support these recommendations, no matter how the nature–nurture question is “resolved,” an argument with which Murray agreed (Miele, 1995). Arthur Jensen, also writing from the hereditarian perspective, recently opined that giving primacy to individual rights maximizes fairness, which he pragmatically defined as the ability of each individual to reach his or her full potential (Miele, 2002). He therefore argued for a restructuring of the educational system by tailoring methods to fit the individual, and letting the group outcomes become what they may, rather than allowing claims of differential performance to justify group rights over individual rights. A multifaceted approach to the policy implications of the hereditarian conclusion about mean Black–White differences is required. Many policy preferences are not at all affected by our scientific conclusion. Granting equal rights under the law and whether to provide social welfare, for example, are based more on moral and political philosophy than on research findings. Still other policy issues (e.g., affirmative action, the value of diversity) might merit reconsideration based on the degree to which heredity as opposed to culture turns out to be the causal agent. Finally, certain policies do follow from our conclusions, such as the need for greater equality and neutrality in the treatment of the culture-only and genetic hypothesis within both the scientific and policy arenas, and in researching and ameliorating the biological basis of group differences in IQ, health, and so on. Two fundamentally different, policy-organizing models typically used to explain why racial groups differ in average rate of socially valued outcomes should be examined, specifically, with reference to the issues of race relations, educational and psychological testing, health, and conflicting worldviews about the nature of human nature. > > Discrimination or Distribution? > … For reference, here is an excerpt from a typical journal in Education: “In discussing racial and ethnic gaps, we focus on three groups: Hispanics, non-Hispanic whites (whites), and non-Hispanic African Americans (blacks). We note that these groups are socially constructed and heterogeneous categories that proxy for diverse ethnic and cultural groups… I **n the United States, the Hispanic and black categories serve as markers for minority status and its accompanying experiences of discrimination and disadvantage** … … **Other changes would also improve black and Hispanic children’s school readiness, but would not reduce racial and ethnic gaps much, because they would also improve white children’s achievement. If raising black and Hispanic children’s school readiness regardless of their relative levels of achievement is a goal, then these changes should be considered**. (Magnuson and Waldfogel.Early Childhood Care and Education: Effects on Ethnic and Racial Gaps in School Readiness) If differences are conceived as due to discrimination than counter discrimination is see as good. That entails not treating individuals as individuals. This is the logic that the OP is challenging. (By challenging the first premise). ---
**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:** [June 21, 2012, 7:41pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/663 "2012-06-21T19:41:10Z")
> [@Chuck11](#): > > (1) So this is what the authors of the article I cited said: > > “Here, we evaluated the level of population differentiation for human genes on autosomal chromosomes among three populations: **African, European and East Asian** , based on the HapMap data (Phase II) [4], using the parameter FST according to methods described previously [3,5].” > > So they didn’t mention Negroids, Caucasoids, and Mongoloids. You got me there! > > (2) I’m glad to hear that most experts are aware of me and my opinions. I will have to assume you concede the other points I mentioned, in any case the focus is in medical conditions not intelligence. And I can not forget that in a previous discussion when scientists are inquired they report that any use of geographical location or ethnicity are just for explanation purposes. They agree that there is only one race when biology is concerned. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [June 21, 2012, 8:39pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/664 "2012-06-21T20:39:15Z")
> [@iiandyiiii](#): > > That’s a pretty difficult claim to make “no Negroids will ever be found to be more genetically similar to a non-Negroids than to a Negroid”- I don’t think evidence support this… though you could be deliberately stating it as a tautology (e.g. that your definition of Negroid requires this), but I can’t tell. > > You’re saying that there are zero sub-Saharan African populations who have (as a population) a more recent common ancestor outside of Africa than inside Africa? > [@iiandyiiii](#): > > That’s a pretty difficult claim to make “no Negroids will ever be found to be more genetically similar to a non-Negroids than to a Negroid”- I don’t think evidence support this… though you could be deliberately stating it as a tautology (e.g. that your definition of Negroid requires this), but I can’t tell. > > You’re saying that there are zero sub-Saharan African populations who have (as a population) a more recent common ancestor outside of Africa than inside Africa? I was being semi-tautological. I was referring to this paper: [http://www.genetics.org/content/176/1/351.full](http://www.genetics.org/content/176/1/351.full) > [@](#): > > Thus the answer to the question “How often is a pair of individuals from one population genetically more dissimilar than two individuals chosen from two different populations?” depends on the number of polymorphisms used to define that dissimilarity and the populations being compared. The answer, can be read from Figure 2. Given 10 loci, three distinct populations, and the full spectrum of polymorphisms (Figure 2E), the answer is ≅ 0.3, or nearly one-third of the time. With 100 loci, the answer is ∼20% of the time and even using 1000 loci, ≅ 10%. However, if genetic similarity is measured over many thousands of loci, the answer becomes “never” when individuals are sampled from geographically separated populations. The caveat is that we are dealing with geographically separated populations. Geographic races were – except in the historic hybrid zones. In those zones you will find the people and populations that you are talking about. But those people and populations have typically been understood as hybrids in the OPs racial taxonomy (which is just the classic geographic=zoological race taxonomy). (What I was responding to was your link about mtDNA.and the suggestion that some Black West Africans are more genetically similar to some, say, Yellow East Asians. None are, when you look at enough genes.) ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [June 21, 2012, 8:59pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/665 "2012-06-21T20:59:13Z")
> [@GIGObuster](#): > > They agree that there is only one race when biology is concerned. What they think probably depends, as we said, on what [part of the world](http://lesacreduprintemps19.files.wordpress.com/2011/07/on-the-concept-of-race-in-chinese-biological-anthropology-alive-and-well.pdf) they are from. ---
**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:** [June 21, 2012, 9:42pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/666 "2012-06-21T21:42:20Z")
> [@Chuck11](#): > > (What I was responding to was your link about mtDNA.and the suggestion that some Black West Africans are more genetically similar to some, say, Yellow East Asians. None are, when you look at enough genes.) I don’t think the link says that exactly- I took it to be only about specific geographic populations. Plus, if the “Out of Africa” theory is true, one would expect that some populations that never left Africa (or alternately left and came back) would be more closely related to the populations that did leave then some of the far-flung populations that split off before any left Africa. For example- if population X split into Xa, Xb, and Xc, and then Xc split into Xca and Xcb, and Xcb left Africa (and split into “whites” and “Asians”), then one would expect that the descendants of population Xca are closer to Eurasians than to Xa and Xb. ---
**Author:** ![Great\_Antibob](https://avatars.discourse-cdn.com/v4/letter/g/e47c2d/32.png) [@Great\_Antibob](https://boards.straightdope.com/u/Great_Antibob)\ **Post date:** [June 21, 2012, 10:08pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/667 "2012-06-21T22:08:56Z")
> [@Chuck11](#): > > I disagree – The OP is in clear agreement with the statement about treating individuals as individuals. Really? Let me give you a couple examples from the Pit Thread: > [@SDMB Bigoted Asshole Omnibus Thread](https://boards.straightdope.com/t/sdmb-bigoted-asshole-omnibus-thread/623489/1500): > > No Negro author compares with Homer, the Greek tragic dramatists, Dante, or Shakespeare, not to mention the giants of Russian literature. So, the OP is pretty much dead set on the idea that even individual “Negro author” could ever possibly accomplish something grand. That’s a pretty broad statement to make about all possible “Negro” individuals and pretty much establishes that the OP equates individual performance with average performance in “Negroes”. Also: > [@SDMB Bigoted Asshole Omnibus Thread](https://boards.straightdope.com/t/sdmb-bigoted-asshole-omnibus-thread/623489/1859): > > Pushkin and Back Obama are mulattoes who owe their high IQ genes to white ancestry. Note that Barack Obama’s father was smart enough to study abroad and pursue graduate studies. Doesn’t sound like the OP really thinks even individual blacks can possibly be intelligent. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [June 21, 2012, 10:21pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/668 "2012-06-21T22:21:45Z")
> [@iiandyiiii](#): > > I don’t think the link says that exactly- I took it to be only about specific geographic populations. Plus, if the “Out of Africa” theory is true, one would expect that some populations that never left Africa (or alternately left and came back) would be more closely related to the populations that did leave then some of the far-flung populations that split off before any left Africa. For example- if population X split into Xa, Xb, and Xc, and then Xc split into Xca and Xcb, and Xcb left Africa (and split into “whites” and “Asians”), then one would expect that the descendants of population Xca are closer to Eurasians than to Xa and Xb. I’ll have to think about your point and get back to you on it. Most discussions I’ve read considered it to apply to broad continental populations just as well as to small subcontinental ones. A continental population is just a grouping of “specific populations” in the way that a specific population is a grouping of a set of individuals. So I don’t see why similarity wouldn’t scale up if you will. But maybe I’m not thinking about it right. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [June 21, 2012, 10:30pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/669 "2012-06-21T22:30:41Z")
> [@iiandyiiii](#): > > I don’t think the link says that exactly- I took it to be only about specific geographic populations. Plus, if the “Out of Africa” theory is true, one would expect that some populations that never left Africa (or alternately left and came back) would be more closely related to the populations that did leave then some of the far-flung populations that split off before any left Africa. For example- if population X split into Xa, Xb, and Xc, and then Xc split into Xca and Xcb, and Xcb left Africa (and split into “whites” and “Asians”), then one would expect that the descendants of population Xca are closer to Eurasians than to Xa and Xb. I’ll have to think about your point and get back to you on it. Most discussions I’ve read considered it to apply to broad continental populations just as well as small subcontinental ones. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [June 21, 2012, 10:38pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/670 "2012-06-21T22:38:11Z")
> [@Great\_Antibob](#): > > Really? > > Let me give you a couple examples from the Pit Thread: > > So, the OP is pretty much dead set on the idea that even individual “Negro author” could ever possibly accomplish something grand. > > That’s a pretty broad statement to make about all possible “Negro” individuals and pretty much establishes that the OP equates individual performance with average performance in “Negroes”. > > Also: > > Note that Barack Obama’s father was smart enough to study abroad and pursue graduate studies. > > Doesn’t sound like the OP really thinks even individual blacks can possibly be intelligent. I was under the mistaken impression that “the OP” referred to the authors of the article that NDW cited (e.g., Rushton and Jensen), not NDW himself. That could explain some of the confusion that I’ve had. I know for a fact that Rushton and Jensen never made some of the claims ascribed to “the OP” – but I just assumed that some of you were just misrepresenting them. Ok, if so, sorry for any confusion people. ---
**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:** [June 21, 2012, 10:40pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/671 "2012-06-21T22:40:59Z")
> [@Chuck11](#): > > I’ll have to think about your point and get back to you on it. Most discussions I’ve read considered it to apply to broad continental populations just as well as to small subcontinental ones. A continental population is just a grouping of “specific populations” in the way that a specific population is a grouping of a set of individuals. So I don’t see why similarity wouldn’t scale up if you will. But maybe I’m not thinking about it right. While continents are a convenient way to divide people up, they’ve never been impassible barriers between populations. North Africans and East Africans have been trading and almost certainly exchanging DNA along the Nile for thousands of years of recorded history, and probably far more prehistory. Same with connections between the Horn of Africa and the Arabian Peninsula, or between the Sahel and the Gibraltar region, and across into Iberia. So it seems like one could divide up other areas and call the “races” just as easily- (for example, the Horn of Africa and Arab Peninsula, or Sahel, Western Sahara, Gibraltar, and Iberian Peninsula)- and you might see the same sort of in-group out-group genetic relationships. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [June 21, 2012, 10:50pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/672 "2012-06-21T22:50:39Z")
> [@Chuck11](#): > > I’ll have to think about your point and get back to you on it. Most discussions I’ve read considered it to apply to broad continental populations just as well as to small subcontinental ones. A continental population is just a grouping of “specific populations” in the way that a specific population is a grouping of a set of individuals. So I don’t see why similarity wouldn’t scale up if you will. But maybe I’m not thinking about it right. Isn’t the genetic distance between African populations typically found to be smaller than the genetic distance between African and non-Africans? > **[Whole-Genome Genetic Diversity in a Sample of Australians with Deep...](https://pmc.ncbi.nlm.nih.gov/articles/PMC2917718/figure/fig1/)** > > Australia was probably settled soon after modern humans left Africa, but details of this ancient migration are not well understood. Debate centers on whether the Pleistocene Sahul continent (composed of New Guinea, Australia, and Tasmania) was first... This is why one gets the clustering: > [@](#): > > Measures of population structure on a global level indicate that only ~10%–16% (Wright’s fixation index, FST = 0.10–0.16) of observed genetic variation is due to differences among populations from Africa, Europe, and Asia (26, 40, 206, 228). Analysis of population structure using the program STRUCTURE, (162,) based on 1048 individuals from the CEPH human diversity panel genotyped for 993 genome-wide microsatellite and insertion/deletion markers, indicates that individuals cluster into five major geographic regions: Africa, Europe/Middle East, East Asia, Oceania, and the New World (175). Two recent studies of \>500,000 SNPs genotyped in the CEPH diversity panel support these initial findings (93, 111). Analyses within the African populations indicate that additional substructure exists, particularly between hunter-gatherer and agriculturalist populations (93, 111). However, the CEPH diversity panel includes just eight African populations, four of which are agricultural Bantu-speakers likely to share recent common ancestry (Figure 1). Thus, results from these studies may not reflect the full extent of population structure within Africa. > **[AFRICAN GENETIC DIVERSITY: Implications for Human Demographic History, Modern...](https://pmc.ncbi.nlm.nih.gov/articles/PMC2953791/)** > > Comparative studies of ethnically diverse human populations, particularly in Africa, are important for reconstructing human evolutionary history and for understanding the genetic basis of phenotypic adaptation and complex disease. African ... Those 5 major clusters are identical to the classical geographic races. The populations comprising them should be more genetically similar than not else they would not cluster. ---
**Author:** ![Great\_Antibob](https://avatars.discourse-cdn.com/v4/letter/g/e47c2d/32.png) [@Great\_Antibob](https://boards.straightdope.com/u/Great_Antibob)\ **Post date:** [June 21, 2012, 10:54pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/673 "2012-06-21T22:54:43Z")
> [@Chuck11](#): > > I was under the mistaken impression that “the OP” referred to the authors of the article that NDW cited (e.g., Rushton and Jensen), not NDW himself. Yeah, “OP” = Original Post / Original Poster. Some of your comments make more sense now, since they didn’t match what NDD was claiming. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [June 22, 2012, 3:28am UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/674 "2012-06-22T03:28:36Z")
> [@New\_Deal\_Democrat](#): > > I certainly do not disagree with you. I have never advocated that anyone be discriminated against on the basis of race alone. I do think people should be discriminated against and in favor of on the basis of what correlates with race, such as intelligence, criminal history, or in the case of your example, athletic talent. Waitaminnit now. Why should stupid people be discriminated against? They have enough troubles as it is. Why should people with criminal history be discriminated against? The law is hard enough on them as it is. Why should people lacking athletic talent be discriminated against? **Most** people lack athletic talent, it’s enough that they can’t make the team. ---
**Author:** ![magellan01](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@magellan01](https://boards.straightdope.com/u/magellan01)\ **Post date:** [June 22, 2012, 6:28am UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/675 "2012-06-22T06:28:24Z")
> [@BrainGlutton](#): > > Waitaminnit now. Why should stupid people be discriminated against? They have enough troubles as it is. Why should people with criminal history be discriminated against? The law is hard enough on them as it is. Why should people lacking athletic talent be discriminated against? **Most** people lack athletic talent, it’s enough that they can’t make the team. My guess is that you missed the bolded portion. (bolding mine) [QUOTE=New Deal Democra] I certainly do not disagree with you. I have never advocated that anyone be discriminated against on the basis of race alone. I do think people should be discriminated against **and in favor of** on the basis of what correlates with race, such as intelligence, criminal history, or in the case of your example, athletic talent. [/QUOTE] ---
**Author:** ![New\_Deal\_Democrat](https://avatars.discourse-cdn.com/v4/letter/n/9d8465/32.png) [@New\_Deal\_Democrat](https://boards.straightdope.com/u/New_Deal_Democrat)\ **Post date:** [June 22, 2012, 10:43am UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/676 "2012-06-22T10:43:40Z")
> [@BrainGlutton](#): > > Waitaminnit now. Why should stupid people be discriminated against? They have enough troubles as it is. Why should people with criminal history be discriminated against? The law is hard enough on them as it is. Why should people lacking athletic talent be discriminated against? **Most** people lack athletic talent, it’s enough that they can’t make the team. Stupid people should not be hired for jobs that require intelligence. People who lack athletic talent should not be given athletic scholarships and positions on professional teams. Employers should have the option to not hire ex convicts, and landlords should have the option not to rent to them, because they often have high recidivism rates. This is particularly true for sex offenders and violent criminals. ---
**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:** [June 22, 2012, 1:00pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/677 "2012-06-22T13:00:30Z")
> [@New\_Deal\_Democrat](#): > > Stupid people should not be hired for jobs that require intelligence. People who lack athletic talent should not be given athletic scholarships and positions on professional teams. Employers should have the option to not hire ex convicts, and landlords should have the option not to rent to them, because they often have high recidivism rates. This is particularly true for sex offenders and violent criminals. Should employers and landlords have the right to reject an applicant strictly because of his or her “race”? ---
**Author:** ![ralph124c](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ralph124c](https://boards.straightdope.com/u/ralph124c)\ **Post date:** [June 22, 2012, 2:53pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/678 "2012-06-22T14:53:35Z")
Kinda related, but I remember seeing a TV show, where they were talking about racial genetic characteristics. They were interviewing a black transplant surgeon, who mentioned that of all racial groups, it was hardest to find good tissue matches for African-Americans…this was due to that fact that Africans have much less genetic variability. Why would this be? When Africans migrated out of Africa, what happened to make their descendent’s DNA more diverse? ---
**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:** [June 22, 2012, 3:25pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/679 "2012-06-22T15:25:57Z")
> [@ralph124c](#): > > Kinda related, but I remember seeing a TV show, where they were talking about racial genetic characteristics. They were interviewing a black transplant surgeon, who mentioned that of all racial groups, it was hardest to find good tissue matches for African-Americans..this was due to that fact that Africans have much less genetic variability. > Why would this be? When Africans migrated out of Africa, what happened to make their descendent’s DNA more diverse? This is false- [sub-Saharan African contains the most genetic diversity among humans](http://en.wikipedia.org/wiki/Human_genetic_variation#Phenotypic_variation); in fact, there’s more genetic diversity in SSA then in the rest of the world put together. It’s likely you remember the TV show wrong- the doctor was probably saying it was hardest to find good tissue matches for African Americans because Africans have much **more** genetic diversity. If they had much less, it would actually be much easier to find tissue matches (the easy example is siblings- there’s not that much genetic difference between siblings, so they are often the best choice for tissue transplants). ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [June 22, 2012, 3:27pm UTC](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236/680 "2012-06-22T15:27:07Z")
> [@ralph124c](#): > > it was hardest to find good tissue matches for African-Americans..this was due to that fact that Africans have much less genetic variability. > Why would this be? The majority of African-Americans have ancestry from a small subset of African populations. [Previous page](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236.md?page=33) [Next page](https://boards.straightdope.com/t/race-differences-in-average-iq-are-largely-genetic/623236.md?page=35)