# Are there any proven hereditary psychological differences (intelligence or other) between "races"? **URL:** \ **Category:** Great Debates\ **Created:** [March 17, 2010, 5:20pm UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771 "2010-03-17T17:20:57Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [March 17, 2010, 11:11pm UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/21 "2010-03-17T23:11:21Z")
> [@marshmallow](#): > > My bad. > > Is it at all controversial to state that Southeast Asians and Ashkenazi Jews are tops when it comes to IQ tests? I’ve heard that a lot but I’ve never really looked into it. It is, I’m sure, if you also state the difference has a hereditary basis. E.g., it is perfectly true that black Americans score lower than white Americans on IQ tests, on average, the one group forming a bell curve to the left of the other’s; that is thoroughly documented and not at all controversial. Any explanation you conceivably can give for that, however, **is** controversial (and any public-policy implication you might be tempted to draw from it, even more so). ---
**Author:** ![Kimstu](https://avatars.discourse-cdn.com/v4/letter/k/ecd19e/32.png) [@Kimstu](https://boards.straightdope.com/u/Kimstu)\ **Post date:** [March 18, 2010, 12:21am UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/22 "2010-03-18T00:21:26Z")
> [@John\_Mace](#): > > Yes. Race does not exist as a biological concept. It’s a social construct. And so, it would be odd to look for genetic differences in groups that are not defined genetically. Yup. ISTM that advocates of the existence of heritable psychological/cognitive differences between racial groups (Man, that’s a pain to type every time. Can we just call them HPCDBRGs for short? :)) are basically operating on a combination of two well-known reliable facts and one rather dubious speculative inference, as follows: **Well-Known Reliable Fact 1:** _ **Close** genetic kinship correlates very strongly with similarity **even in hard-to-define psych/cog qualities like intelligence.** _ Even though we can’t (yet) figure out the exact ways that things like intelligence and personality and tastes are passed along genetically, we can be pretty sure that they’re genetically influenced. If your parents are very smart, you’re more likely to be very smart. If your identical twin is a quiet thoughtful type, you’re more likely to be a quiet thoughtful type—and this holds true even if you and your twin were separated at birth and raised in different families. Cognitive and psychological characteristics can be at least partly heritable even if we don’t really understand how they’re inherited. **Well-Known Reliable Fact 2:** _Racial similarity correlates **to some extent** with similarity in certain genetic traits._ These are the indicators of some better-than-purely-random degree of genetic kinship within specific racial categories that we’ve all heard of. E.g., people racially classified as “black” are more likely than the general population to have the gene for sickle-cell trait (as are members of certain other subgroups, but let’s not get into that now). People racially classified as “Asian” are less likely than the general population to have the gene for lactase persistence (that is, they’re more likely to be lactose-intolerant). So clearly, racial similarity must be at least **somewhat** linked to genetic similarity, at least in a lot of specific populations within racial groups. So far so good. However, now we come to the **Dubious Speculative Inference:** _Therefore, it may be reasonably concluded that differences between different racial groups in measured levels of abstract but (at least partially) heritable psych/cog qualities such as IQ are due to innate genetic differences between racial groups._ :dubious: :dubious: :dubious: This inference, IMHO, requires a **lot** of jumping to conclusions. ---
**Author:** ![Cheesy\_goodness](https://avatars.discourse-cdn.com/v4/letter/c/ed8c4c/32.png) [@Cheesy\_goodness](https://boards.straightdope.com/u/Cheesy_goodness)\ **Post date:** [March 18, 2010, 1:54am UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/23 "2010-03-18T01:54:43Z")
> [@Kimstu](#): > > The trouble is that the more narrowly we define something we call “intelligence” as a testable quality, the easier it is to measure it, but the less it reflects the whole spectrum of abilities that we commonly associate with intelligence. > > For instance, verbal abilities are certainly associated with intelligence and are certainly of interest to schools and employers, but they aren’t captured in tests focusing on math and spatial skills. Currently, the most valid and reliable IQ tests are based on something called CHC theory. This theory says that the general intelligence factor, _g_, is divided into several broad abilities. Among these are crystallized intelligence, or acculturated knowledge such as vocabulary and other general knowledge, and fluid intelligence which is a person’s ability to use novel information in novel situations to come to a correct solution. It also includes things like long and short term memory, processing speed, and visual-spatial thinking. IQ tests are exponentially better and more sensitive than they were even 10 or 15 years ago. The best ones such as the Woodcock-Johnson (heh) measure what the general scientific consensus holds to be all areas of intelligence, including verbal and mathematical skills. IQ, as the construct exists today, is very highly correlated with things like academic and first year job success, income level, and incarceration rates. I’m certainly not saying that other kinds of intelligences don’t exist (see Howard Gardner’s theory of multiple intelligences). Also, many tests around today have a considerable amount of cultural and linguistic loading to them, which may account for some of the discrepancies in performance between racial and socioeconomic status groups. I’m a firm believer that if everyone had equality of educational opportunity, a lot of the spread we see between different groups would go back to a more normally distributed shape. I seem to have gone off on a bit of a tangent there but I’m an education/statistics nerd. ---
**Author:** ![code\_grey](https://avatars.discourse-cdn.com/v4/letter/c/f4b2a3/32.png) [@code\_grey](https://boards.straightdope.com/u/code_grey)\ **Post date:** [March 18, 2010, 2:41am UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/24 "2010-03-18T02:41:47Z")
this test captures this, that test captures that… It’s hard to debate with people who don’t know the basic concepts in the field. And one of those basic concepts is that math test scores and verbal test scores correlate - that’s how this whole g concept came about. But of course, if you don’t give a damn about what all those evil scientists cooked up and instead focus on the rhetorical shenanigans of Malcolm Gladwell and his ilk, that will become obvious in your manner of “argument”. ---
**Author:** ![Chen019](https://avatars.discourse-cdn.com/v4/letter/c/f19dbf/32.png) [@Chen019](https://boards.straightdope.com/u/Chen019)\ **Post date:** [March 18, 2010, 3:23am UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/25 "2010-03-18T03:23:50Z")
> [@John\_Mace](#): > > Yes. Race does not exist as a biological concept. It’s a social construct. And so, it would be odd to look for genetic differences in groups that are not defined genetically. This like saying adolescence is a social concept so has no biological significance. Similar with age and gender. They are both social contructs which have biological significance. Self identified race almost perfectly corresponds to genetic clusters associated with the traditional continental racial groups. > [@](#): > > Numerous recent studies using a variety of genetic markers have shown that, for example, individuals sampled worldwide fall into clusters that roughly correspond to continental lines, as well as to the commonly used self-identifying racial groups: Africans, European/West Asians, East Asians, Pacific Islanders, and Native Americans (Bowcock et al. 1994; Calafell et al. 1998; Rosenberg et al. 2002). > > 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**. > **[Genetic Structure, Self-Identified Race/Ethnicity, and Confounding in...](https://pmc.ncbi.nlm.nih.gov/articles/PMC1196372/)** > > We have analyzed genetic data for 326 microsatellite markers that were typed uniformly in a large multiethnic population-based sample of individuals as part of a study of the genetics of hypertension (Family Blood Pressure Program). Subjects ... The implication is that genes occur in different frequencies across groups leading to average group differences. There is also evidence of recent selection as groups adapted to different environments. [PLOS Genetics](http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.0030090) > [@](#): > > \*\*BrainGlutton \*\* wrote > > We’re talking about psychological differences between races here. Any racial differential in sports talent would be based on physical differences, which are more obvious, and beside the point. > > And, of course, top athletes are never a fair representative sample of their racial group’s physical attributes anyway; they’re outliers on that bell curve by definition. This is what you see when groups have different averages. At the upper end of the distribution you see significant differences. For example, while there is greater difference between the tallest man and the shortest man than the average height difference between male & females. But if you look at people over 6 feet tall, a far greater proportion will be men than women. In terms of intelligence, Steve Hsu gives this example: > [@](#): > > If two groups differed by, say, 10 points in average IQ (2/3 of a standard deviation), the respective distributions would overlap quite a bit (more in-group than between-group variation), but the fraction of people with IQ above some threshold (e.g., \>140) would be radically different. It has been claimed that 20% of all Americans with IQ \> 140 are Jewish, even though Jews comprise only 3% of the total population. [Information Processing: "No scientific basis for race"](http://infoproc.blogspot.com/2008/01/no-scientific-basis-for-race.html) > [@](#): > > Brain Glutton wrote: > > 1. Is there, at this date, any hard, scientific evidence of any hereditary psychological differences between different human “races,” however defined? (As in the 2004 thread, I’m asking not just for differences in intelligence, but psychological differences of any kind.) The issue was discussed an debated here. There is a lot of material in the lead article which takes a while to wade through. Psychology, Public Policy, and Law, 11, 235-294. [http://www.udel.edu/educ/gottfredson/30years/](http://www.udel.edu/educ/gottfredson/30years/) There is also some research showing groups differ in average self esteem. > [@](#): > > UNC-CH psychologists analyzed 261 studies in which self-esteem in both white and black children was assessed. The studies involved more than a half-million participants. > > “Our analyses revealed slightly higher scores for combined black children, adolescents and young adults than for their white counterparts,” said Dr. Bernadette Gray-Little, professor of psychology. “The analyses further revealed that such characteristics as age and socioeconomic status influenced the size and direction of racial differences in self-esteem.” [http://www.unc.edu/news/archives/jan00/graylit012400.htm](http://www.unc.edu/news/archives/jan00/graylit012400.htm) ---
**Author:** ![Chief\_Pedant](https://avatars.discourse-cdn.com/v4/letter/c/a6a055/32.png) [@Chief\_Pedant](https://boards.straightdope.com/u/Chief_Pedant)\ **Post date:** [March 18, 2010, 3:31am UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/26 "2010-03-18T03:31:20Z")
> [@kingbighair](#): > > **Chen019** and **Chief Pendant** are the ones usually showing up to prove why their race is the best. Be prepared to 1. get a wall of text that has nothing to do with the topic from **Chen** and 2. explain why there are no white players in the NBA to **Chief**. The characterization of my position as one holding that my race is “best” is unfortunate and wrong. What I have said elsewhere is: 1. Race is a relatively loose category; the more tightly a population is defined, the more certainty there is around the ability to define differences. 2. There are average differences among populations that reflect innate/nature/genetically-determined maximum abilities for various skillsets 3. Within reason there exist populations where nurturing differences have been normalized between groups with enough certainty to suggest that disparate outcomes reflect those underlying innate differences 4. There are rank-orders among populations that cross national and political and nurturing boundaries which support a contention that some populations–even populations defined as grossly as “race” defines them–contain a disproportionate distribution of genes enabling disproportionate representations for specific skillsets. The NBA and sprinting for “blacks” (and in particular, blacks of West African descent) are examples. That particular population is over-represented around the world for the skillset of sprinting, for example. 5. G is largely inherited and therefore intelligence differences measured among various populations reflect innate differences more than nurturing differences. Normalization of nurturing (for instance, studies showing that children of wealthy and educated black Americans underperform children born to poor and undereducated white Americans on SATs) lends support to the hypothesis that differences are not primarily due to nurture 6. Regression toward the mean of children born to parents at either end of the IQ spectrum lends credence to the heretitable nature of G. 7. Overall national economic success in countries not primarily dependent on selling a natural resource for their wealth seems to correlate well with both specific measurements of IQ, and even within countries not as successful on a national scale one can find pockets of innovation or niche successes that suggest a strong disparity of distribution for an intelligence-based skillset. An example might be the remarkable success India has had exporting their brainpower in the field of Information Technology versus any analagous success exporting brainpower-related skills or innovation pockets in sub-saharan countries. 8. “Whites” as a “race” seem to fall somewhere in the middle on a broad scale for most educational skillsets, typically outperforming “blacks” and underperforming South and East Asians in math-related fields, for example. 9. It is not necessary for a population to be related within itself for the differences between that population and another to be ascribed to genes. I’ve used a common example of “tall.” The population of tall people is taller than the population of short people because of innate genetic differences and not nurture, despite the fact that all tall people are not otherwise a genetic family. To the point of the OP, it’s my personal opinion that many “psychological” differences are innate/genetic. As I have said elsewhere, we are our genes, mostly. Our genes determine how we will be shaped by our nurturing; it is for this reason two people born to the same abusive parent may have differening outcomes. If we look at schizophrenia, we find that there are probably genes underlying the disorder; if for schizophrenia, why not less severe disorders? If we neuter a male animal we find that the aggression of that animal changes to the point where its personality changes. This is a function of physical/innate change versus simply a shaping of the animal’s personality by its environment. When we look at breeds of dogs we readily see personality profiles which vary among the breeds; this seems like a perfectly good laboratory experiment that genes determine those psychologic profiles. If we administer medications to certain personalities we find that the personalities change. It seems reasonable to draw an inference that there are chemicals and physical processes which underlie what we call “psychological differences” and our genes are a major contributor to our endogenous chemicals and our assorted neurologic pathways. Moreover, I find it a personal observation that personalities not uncommonly seem to be quite familial. For those who demand precise biologic pathways and gene definitions before they will accept that we are our genes, I have a simple answer: no problem. Be careful, however, assuming that such elucidation is so far off that your paradigm cannot be changed anytime soon. The human genome is being unraveled. I understand that in the interim you may not see the evidence the way I do. To those who wish to triumph their race as some sort of personal success story as if they had a part in choosing which geneset to be born to, and as if being born to a particular race or geneset is an accomplishment, I have a different comment: Look up the word “idiot.” To the rest I simply say: we are all human and we all need to take care of one another. Such altruism does not require us to pretend there cannot be genetically determined differences among populations. I do not personally give a rat’s ass what race you are, or think you are, or wish you were. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [March 18, 2010, 3:59am UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/27 "2010-03-18T03:59:32Z")
> [@Chief\_Pedant](#): > > 1. G is largely inherited and therefore intelligence differences measured among various populations reflect innate differences more than nurturing differences. Normalization of nurturing (for instance, studies showing that children of wealthy and educated black Americans underperform children born to poor and undereducated white Americans on SATs) lends support to the hypothesis that differences are not primarily due to nurture Cite? ---
**Author:** ![Kimstu](https://avatars.discourse-cdn.com/v4/letter/k/ecd19e/32.png) [@Kimstu](https://boards.straightdope.com/u/Kimstu)\ **Post date:** [March 18, 2010, 3:59am UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/28 "2010-03-18T03:59:45Z")
> [@Chief Pedant](#): > > 1. It is not necessary for a population to be related within itself for the differences between that population and another to be ascribed to genes. I’ve used a common example of “tall.” The population of tall people is taller than the population of short people because of innate genetic differences and not nurture, despite the fact that all tall people are not otherwise a genetic family. Sure, but that applies ONLY to the **particular genetic difference you happen to be using to define the “population”** , not to any other genetic differences that are unrelated to it. Yes, the population of tall people is taller than the population of short people, and that difference is genetic. Similarly, the population of black people is blacker than the population of white people, and that difference is genetic. No surprise there. But you can’t therefore assume any **other** genetic difference between the two populations you’re comparing that isn’t directly linked to the difference you’re using to define them (height in the one case, skin color in the other). For instance, you can’t infer that the tall population is on average more likely than the short population to carry the sickle-cell trait, because that’s a genetic trait that’s not directly linked to tallness. The tall Masai have it but the tall Dutch don’t, for example. Likewise, you can’t infer that the white population is on average more intelligent than the black population, because so far, nobody’s convincingly shown any genetic mechanism linking skin color with intelligence. As I said above, the problem’s not with the recognized facts about race and genetics, the problem’s with the dubious inference you’re attempting to draw from them. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [March 18, 2010, 4:31am UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/29 "2010-03-18T04:31:44Z")
> [@Chen019](#): > > This like saying adolescence is a social concept so has no biological significance. Similar with age and gender. They are both social contructs which have biological significance. Need details. Why is this a good analogy? > [@](#): > > Self identified race almost perfectly corresponds to genetic clusters associated with the traditional continental racial groups.] Well, sure. That works great on average. But you can’t draw a line on a map and say that people on this side of the line are Group A and people on the other side of the line are Group B. If you walk from Beijing to Berlin, where do people stop being Asian and start being European? It’s an arbitrary boundary. ---
**Author:** ![Chen019](https://avatars.discourse-cdn.com/v4/letter/c/f19dbf/32.png) [@Chen019](https://boards.straightdope.com/u/Chen019)\ **Post date:** [March 18, 2010, 4:36am UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/30 "2010-03-18T04:36:40Z")
> [@John\_Mace](#): > > Need details. Why is this a good analogy? > Well, sure. That works great on average. But you can’t draw a line on a map and say that people on this side of the line are Group A and people on the other side of the line are Group B. If you walk from Beijing to Berlin, where do people stop being Asian and start being European? It’s an arbitrary boundary. Apparently it isn’t that arbitrary if you look at more than 20 genetic markers (also note that forensic pathologists can identify race from the skeleton or skull). > [@](#): > > Genetic data … show that any two individuals within a particular population are as different genetically as any two people selected from any two populations in the world." [18]. This assertion is both counter-intuitive and factually incorrect [12,13]. If it were true, it would be impossible to create discrete clusters of humans (that end up corresponding to the major races), for example as was done by Wilson et al. [2], with even as few as 20 randomly chosen genetic markers. Two Caucasians are more similar to each other genetically than a Caucasian and an Asian." Risch et al. Genome Biol. 2002; 3(7): comment2007.1–comment2007.12. [http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=139378](http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=139378) To get another idea see the clustering and genetic distance shown here: > **[Genetic clustering: 40 years of progress](https://infoproc.blogspot.com/2009/06/genetic-clustering-40-years-of-progress.html)** > > Represent each individual human by their DNA sequence. When aggregated, they cluster into readily identifiable groups. This has been known f... In terms of gender, Risch gives this example here. > [@](#): > > In our own studies, to avoid coming up with our own definition of race, we tend to use the definition others have employed, for example, the US census definition of race. There is also the concept of the major geographical structuring that exists in human populations—continental divisions—which has led to genetic differentiation. But if you expect absolute precision in any of these definitions, you can undermine any definitional system. Any category you come up with is going to be imperfect, but that doesn’t preclude you from using it or the fact that it has utility. > > We talk about the prejudicial aspect of this. If you demand that kind of accuracy, then one could make the same arguments about sex and age! > > You’ll like this. In a recent study, when we looked at the correlation between genetic structure [based on microsatellite markers] versus self-description, we found 99.9% concordance between the two. We actually had a higher discordance rate between self-reported sex and markers on the X chromosome! So you could argue that sex is also a problematic category. And there are differences between sex and gender; self-identification may not be correlated with biology perfectly. And there is sexism. And you can talk about age the same way. A person’s chronological age does not correspond perfectly with his biological age for a variety of reasons, both inherited and non-inherited. Perhaps just using someone’s actual birth year is not a very good way of measuring age. Does that mean we should throw it out? No. Also, there is ageism—prejudice related to age in our society. A lot of these arguments, which have a political or social aspect to them, can be made about all categories, not just the race/ethnicity one. [PLOS Genetics](http://www.plosgenetics.org/article/info:doi%2F10.1371%2Fjournal.pgen.0010014) ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [March 18, 2010, 4:50am UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/31 "2010-03-18T04:50:28Z")
> [@Chen019](#): > > (also note that forensic pathologists can identify race from the skeleton or skull) This is entirely unremarkable. Racial classifications are based largely on superficial physical features. Forensic pathologists are use skeletal features to narrow down the nature of those superficial features with sufficient accuracy to usually get racial classification right. That alone doesn’t provide any basis for arguing that race is a real biological/genetic category, just that there are strong correlations between race and superficial features - which is hardly news to anyone. ---
**Author:** ![ragerdude](https://avatars.discourse-cdn.com/v4/letter/r/d07c76/32.png) [@ragerdude](https://boards.straightdope.com/u/ragerdude)\ **Post date:** [March 18, 2010, 4:56am UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/32 "2010-03-18T04:56:59Z")
> [@Ruminator](#): > > Until some type of breakthrough proactive biological technology comes to light, it doesn’t seem like any rhetoric will convince either side. It’s like asking people of 3000 years ago to determine if the Sun rotates around the Earth or vice versa but nobody has any telescopes. Telescopes aren’t necessary to demonstrate the superiority of heliocentrism. ---
**Author:** ![Chen019](https://avatars.discourse-cdn.com/v4/letter/c/f19dbf/32.png) [@Chen019](https://boards.straightdope.com/u/Chen019)\ **Post date:** [March 18, 2010, 5:05am UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/33 "2010-03-18T05:05:22Z")
> [@](#): > > Originally Posted by Chen019 > (also note that forensic pathologists can identify race from the skeleton or skull) > > Gorsnak wrote: > > This is entirely unremarkable. Racial classifications are based largely on superficial physical features. Forensic pathologists are use skeletal features to narrow down the nature of those superficial features with sufficient accuracy to usually get racial classification right. That alone doesn’t provide any basis for arguing that race is a real biological/genetic category, just that there are strong correlations between race and superficial features - which is hardly news to anyone. Right, and it is pretty strong evidence that their ancestors adapted to at least somewhat different environments. And there is no a priori reason to suppose that the optimal physical characteristics were different in those different environments but the optimal mental characteristics were the same. Also, note that brain size correlates with measured mental traits (this differs amongst groups to on average, see Ralph Holloway’s data on page 709). (2009). Whole-brain size and general mental ability: A review. International Journal of Neuroscience, 119, 691-731. [http://psychology.uwo.ca/faculty/rushtonpdfs/2009%20IJN.pdf](http://psychology.uwo.ca/faculty/rushtonpdfs/2009%20IJN.pdf) ---
**Author:** ![Kimstu](https://avatars.discourse-cdn.com/v4/letter/k/ecd19e/32.png) [@Kimstu](https://boards.straightdope.com/u/Kimstu)\ **Post date:** [March 18, 2010, 5:41am UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/34 "2010-03-18T05:41:04Z")
> [@Chen019](#): > > Right, and it is pretty strong evidence that their ancestors adapted to at least somewhat different environments. And there is no a priori reason to suppose that the optimal physical characteristics were different in those different environments but the optimal mental characteristics were the same. No, but I don’t see any _a priori_ reason to suppose that the optimal mental characteristics were different, either. However, I can think of a way to test that hypothesis, at least some aspects of it, that should be fairly straightforward and less liable to nature/nurture problems: namely, test for differences in **perceptual** abilities. If people on different continents really evolved within the past ten millennia to think in significantly different ways due to different physical environments, then it seems logical that they evolved to see, hear, smell, etc., in significantly different ways too. Why not do some experiments to see if blacks and Asians, for example, have optimal visual acuity in slightly different parts of the spectrum, or optimal hearing at slightly different frequencies, and so forth? ISTM that such experiments would be much less vulnerable to confounding non-genetic factors than tests of intelligence or academic performance are, and they might give us some hints about where to look in the genes for recently evolved mental differences. Assuming, of course, that they actually showed evidence of any such differences. ---
**Author:** ![Chen019](https://avatars.discourse-cdn.com/v4/letter/c/f19dbf/32.png) [@Chen019](https://boards.straightdope.com/u/Chen019)\ **Post date:** [March 18, 2010, 5:56am UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/35 "2010-03-18T05:56:17Z")
> [@](#): > > Kimstu wrote, > > If people on different continents really evolved within the past ten millennia to think in significantly different ways due to different physical environments, then it seems logical that they evolved to see, hear, smell, etc., in significantly different ways too. Why not do some experiments to see if blacks and Asians, for example, have optimal visual acuity in slightly different parts of the spectrum, or optimal hearing at slightly different frequencies, and so forth? According to Cochran, one of the co-authors of the ‘recent acceleration of adaptive evolution’ paper they do to some extent. I’ll have to try and find the references. > [@](#): > > Populations vary in color-blindness, in the fraction of working olfactory genes, in visual acuity, in susceptibility to myopia. > **[2blowhards.com: A Week with Gregory Cochran: Day Three](http://www.2blowhards.com/archives/2009/01/a_week_with_gre_3.html)** > > 2blowhards.com - a weblog ---
**Author:** ![Inbred\_Mm\_domesticus](https://avatars.discourse-cdn.com/v4/letter/i/aca169/32.png) [@Inbred\_Mm\_domesticus](https://boards.straightdope.com/u/Inbred_Mm_domesticus)\ **Post date:** [March 18, 2010, 7:11am UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/36 "2010-03-18T07:11:22Z")
> [@Chen019](#): > > Self identified race almost perfectly corresponds to genetic clusters associated with the traditional continental racial groups. Going off the abstract, that link pretty much says that allele frequencies of microsatellite markers covary with self-identified race. A couple of things: First, it’s a rare genetic marker that actually has a phenotypic effect on something other than the allele frequency of the genetic marker. Second, the conclusion can be stated as people of a self-identified race are more likely to be related to each other. More generally, people from different populations are more likely to be related to each other. Isn’t this well known? I wonder what would happen if you compared the distributions of these markers among African-Americans to Ethiopians? Or Ghanians? Or Nigerians? Or Madagascarians? Second, what does this factoid have to do with intelligence (or self-esteem)? And don’t just come up with a bunch of “I suppose”'s and “Could be”'s if you bother to answer. Give me solid evidence, because a subject as touchy as this requires it. > [@Chen019](#): > > [2blowhards.com: A Week with Gregory Cochran: Day Three](http://www.2blowhards.com/archives/2009/01/a_week_with_gre_3.html) Color-blindness and olfactory receptors are all regulated by single genes. It’s not surprising that unselected single gene traits (akin to microsatellite markers) would segregate quite readily from one population to another. The real challenge is the multifactorial hurdle. Take a look at this link with an abstract about IQ: [IQ governed by many genes, each with a small effect](http://www3.interscience.wiley.com/journal/118618288/abstract?CRETRY=1&SRETRY=0). Let’s not forget all the environmental factors affecting intelligence. How is it that multiple genes of small effect are being distributed in such a way as to co-segregate and result in a clustering of alleles that affect intelligence in the same direction? In addition: I assume that rats have a similar deal with multiple genes and how well they pass their IQ test: a maze. Didn’t Tryon Maze Bright and Dull rats show little difference in intelligence once raised in enriched environments? These rats were under multiple generations of intense selection pressure yet a simple change in environment led to a near loss of the massive difference in learning. It just doesn’t seem possible that subpopulation differences in IQ can be so well regulated by genes as you suppose, yet be so easily altered by single environmental variables. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [March 18, 2010, 5:04pm UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/37 "2010-03-18T17:04:09Z")
Listening to NPR right now, and they are starting a program on this very subject. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [March 18, 2010, 6:05pm UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/38 "2010-03-18T18:05:38Z")
> [@Chen019](#): > > This like saying adolescence is a social concept so has no biological significance. Similar with age and gender. They are both social contructs which have biological significance. > > Self identified race almost perfectly corresponds to genetic clusters associated with the traditional continental racial groups. > > [Genetic Structure, Self-Identified Race/Ethnicity, and Confounding in Case-Control Association Studies - PMC](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1196372/) > > The implication is that genes occur in different frequencies across groups leading to average group differences. There is also evidence of recent selection as groups adapted to different environments. [PLOS Genetics](http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.0030090) > > This is what you see when groups have different averages. At the upper end of the distribution you see significant differences. For example, while there is greater difference between the tallest man and the shortest man than the average height difference between male & females. But if you look at people over 6 feet tall, a far greater proportion will be men than women. In terms of intelligence, Steve Hsu gives this example: > > [Information Processing: "No scientific basis for race"](http://infoproc.blogspot.com/2008/01/no-scientific-basis-for-race.html) > > The issue was discussed an debated here. There is a lot of material in the lead article which takes a while to wade through. > > Psychology, Public Policy, and Law, 11, 235-294. > > [http://www.udel.edu/educ/gottfredson/30years/](http://www.udel.edu/educ/gottfredson/30years/) > > There is also some research showing groups differ in average self esteem. > > [http://www.unc.edu/news/archives/jan00/graylit012400.htm](http://www.unc.edu/news/archives/jan00/graylit012400.htm) Once again, you are not posting anything showing or tending to show that any measurable and hereditary differential in intelligence or other psychological characteristics between different racial groups **exists.** ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [March 18, 2010, 6:06pm UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/39 "2010-03-18T18:06:41Z")
> [@Chen019](#): > > Apparently it isn’t that arbitrary if you look at more than 20 genetic markers (also note that forensic pathologists can identify race from the skeleton or skull). > > Risch et al. Genome Biol. 2002; 3(7): comment2007.1–comment2007.12. > > [http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=139378](http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=139378) > > To get another idea see the clustering and genetic distance shown here: > > [Information Processing: Genetic clustering: 40 years of progress](http://infoproc.blogspot.com/2009/06/genetic-clustering-40-years-of-progress.html) > > In terms of gender, Risch gives this example here. > > [PLOS Genetics](http://www.plosgenetics.org/article/info:doi%2F10.1371%2Fjournal.pgen.0010014) And again. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [March 18, 2010, 6:08pm UTC](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771/40 "2010-03-18T18:08:16Z")
> [@Chen019](#): > > Right, and it is pretty strong evidence that their ancestors adapted to at least somewhat different environments. And there is no a priori reason to suppose that the optimal physical characteristics were different in those different environments but the optimal mental characteristics were the same. > > Also, note that brain size correlates with measured mental traits (this differs amongst groups to on average, see Ralph Holloway’s data on page 709). > > (2009). Whole-brain size and general mental ability: A review. International Journal of Neuroscience, 119, 691-731. > > [http://psychology.uwo.ca/faculty/rushtonpdfs/2009%20IJN.pdf](http://psychology.uwo.ca/faculty/rushtonpdfs/2009%20IJN.pdf) And again. [Previous page](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771.md?page=1) [Next page](https://boards.straightdope.com/t/are-there-any-proven-hereditary-psychological-differences-intelligence-or-other-between-races/532771.md?page=3)