# 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:** 16\ **Page:** 18
**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:** [September 9, 2011, 12:02am UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/341 "2011-09-09T00:02:22Z")
> [@Chuck11](#): > > You’re obviously not familiar with the research. There’s little evidence that the Flynn effect represents a rise in general intelligence. Of course the Flynn effect doesn’t represent a rise in general intelligence. But this directly implies that IQ tests don’t accurately measure differences in general intelligence unless you control for a large number of unknown social variables. To wit, if the multiple standard deviation difference in IQ score between random American from 1910 and random American from 2010 doesn’t indicate that the latter has higher intelligence than the former, we have little reason to believe that a standard deviation difference in IQ score between random American and random Congolese indicates that the former has higher intelligence than the latter. ---
**Author:** ![NNN99](https://avatars.discourse-cdn.com/v4/letter/n/ac91a4/32.png) [@NNN99](https://boards.straightdope.com/u/NNN99)\ **Post date:** [September 11, 2011, 11:37pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/342 "2011-09-11T23:37:57Z")
Nope. If you look closley at the number of blacks in High School you will find that a large majority do not do the work. This can be attributed to a one parent family, the pechant to run the streets instead of studying. And parents who, well, live off the system. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [September 12, 2011, 12:11am UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/343 "2011-09-12T00:11:35Z")
> [@Gorsnak](#): > > Of course the Flynn effect doesn’t represent a rise in general intelligence. But this directly implies that IQ tests don’t accurately measure differences in general intelligence unless you control for a large number of unknown social variables. It’s established – though twin studies, twins reared apart studies, adoption studies, kinship studies, and now GWAS IQ studies – that differences within populations are largely under genetic control. This conclusion is supported by the copious research on the neurobiology of general intelligence and is now impeachable. This tells us that IQ tests can measure genetic differences and that populations could in principle differ genotypically in IQ. The Flynn effect, though, reminds us that IQ scores can not be taken at face value as an indicator of the level of general intelligence. Populations need to be comparable and this can be shown through statistical analysis. Such as [this](http://www.iapsych.com/wj3ewok/LinkedDocuments/edwards2006.pdf): > [@](#): > > The data from this study suggest that scores on WJ III have comparable meanings across two important examinee subgroups. As such, the instrument satisfies Standards 7.1 and 7.8 governing the fair use of tests with African American and Caucasian American students (AERA et al., 1999). According to these standards, test scores are considered to have comparable meanings across ethnic groups when scores generate similar inferences about examinees who are members of different ethnic groups. Given the current concerns about the use of standardized assessments and placement rates in special education for ethnic minorities, these findings provide some modest support for the integrity of the measure for use with the noted examinee subgroups. Thus, when using the WJ III Cognitive with African American and Caucasian American students, practitioners can be somewhat assured that possible score differences reflect differences in the underlying latent constructs rather than variations in the measurement operation itself (Watkins & Canivez, 2001). To show this, you, of course, do not need to “control for a large number of unknown social variables.” > [@](#): > > To wit, if the multiple standard deviation difference in IQ score between random American from 1910 and random American from 2010 doesn’t indicate that the latter has higher intelligence than the former, we have little reason to believe that a standard deviation difference in IQ score between random American and random Congolese indicates that the former has higher intelligence than the latter Well, there is reason – but it’s largely indirect e.g the correlation between African performance on IQ tests and international achievement tests. We do have plenty of reason to conclude that the average intelligence of European-Americans is higher than that of African-Americans. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [September 12, 2011, 12:30am UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/344 "2011-09-12T00:30:38Z")
> [@tomndebb](#): > > Putting words in my mouth buys you nothing. I noted that using a claim for educational deprivation falls outside the realm of genetics and is not pertinent to this discussion. All the rest is just you trying to game the discussion. I guess I didn’t understand your point. Either you accept that the within population heritability is high or that it’s not. Which is it? Why does this matter? Well, because within population heritability is mathematically related to between population heritability. It contrains enviro explanations. ---
**Author:** ![Paranoid\_Randroid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/paranoid_randroid/32/18_2.png) [@Paranoid\_Randroid](https://boards.straightdope.com/u/Paranoid_Randroid)\ **Post date:** [September 12, 2011, 12:39am UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/345 "2011-09-12T00:39:11Z")
> [@Chuck11](#): > > To show this, you, of course, do not need to "control for a large number of unknown social variables.” What Edwards and Oakland (your chosen example) attempt to show is that IQ scores for white and black Americans have “comparable meaning” — that they measure the same thing. But even granting that thesis would _not_ disprove **Gorsnak** ’s comment, viz. > [@](#): > > this directly implies that IQ tests don’t accurately measure differences in general intelligence unless you control for a large number of unknown social variables. Consider: we are investigating the determinants of body mass index, the “meaning” of which is undeniably the same for whites and for blacks. We note that blacks have (pulling this out of the air — I don’t recall what the actual stats are) a higher BMI by 0.7 points on average. Does this mean that black Americans have an innate, genetic predisposition toward higher BMI? What if — after controlling for education, income, and a host of other socioeconomic variables — we find that the difference disappears? By analogy, your interlocutors are not claiming that BMI measures something different for different populations; they instead claim that the difference in measured BMI is not _built-in_ but rather the result of unobserved confounding. Thus a citation showing that (for example) IQ is comparable between populations is entirely irrelevant. ---
**Author:** ![Chen019](https://avatars.discourse-cdn.com/v4/letter/c/f19dbf/32.png) [@Chen019](https://boards.straightdope.com/u/Chen019)\ **Post date:** [September 12, 2011, 2:27am UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/346 "2011-09-12T02:27:14Z")
> [@Paranoid\_Randroid](#): > > Consider: we are investigating the determinants of body mass index, the “meaning” of which is undeniably the same for whites and for blacks. We note that blacks have (pulling this out of the air — I don’t recall what the actual stats are) a higher BMI by 0.7 points on average. > > Does this mean that black Americans have an innate, genetic predisposition toward higher BMI? What if — after controlling for education, income, and a host of other socioeconomic variables — we find that the difference disappears? By analogy, your interlocutors are not claiming that BMI measures something different for different populations; they instead claim that the difference in measured BMI is not _built-in_ but rather the result of unobserved confounding. > > Thus a citation showing that (for example) IQ is comparable between populations is entirely irrelevant. It’s not irrelevant, it’s a part of the overall argument. Sesardic [explains](http://www.ln.edu.hk/philoso/staff/sesardic/getfile.php?file=POS-2000.pdf): > [@](#): > > Here is Jensen’s argument in a schematic form. > > (A) High WGH of IQ (among both whites and blacks). > > (B) Empirical data (mainly about the relation of certain environmental > variables and IQ). > > (C) Non-zero BGH. > > Critics charge that (C) cannot be inferred from (A). Granted. But making > this point comes nowhere near addressing the real hereditarian argument, > which tries to reach (C) on the basis of both (A) and (B). > > Another thing to keep in mind here: conceding that (C) cannot be inferred > from (A) alone, deductively or probabilistically, should not be taken > to mean (as it sometimes is) that (A) is evidentially irrelevant for the truth > of (C). Jensen’s basic claim is that given (A), the empirical information in > (B) makes (C) more plausible than (not-C). If (A) were false, however, he > thinks that (B) would lose at least some of its force as a reason for accepting (C). > > So, in this picture, (A) is an essential argumentative part of the case for (C) although (A) is by itself insufficient to establish (C). ---
**Author:** ![Gyrate](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gyrate/32/3588_2.png) [@Gyrate](https://boards.straightdope.com/u/Gyrate)\ **Post date:** [September 12, 2011, 10:38am UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/347 "2011-09-12T10:38:20Z")
> [@NNN99](#): > > Nope. If you look closley at the number of blacks in High School you will find that a large majority do not do the work. This can be attributed to a one parent family, the pechant to run the streets instead of studying. And parents who, well, live off the system. At last, a factual argument based on solid evidence and thorough research rather than cheap flimsy stereotypes. Thank heavens you’re here to set us straight. ---
**Author:** ![Paranoid\_Randroid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/paranoid_randroid/32/18_2.png) [@Paranoid\_Randroid](https://boards.straightdope.com/u/Paranoid_Randroid)\ **Post date:** [September 12, 2011, 1:48pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/348 "2011-09-12T13:48:51Z")
> [@Chen019](#): > > It’s not irrelevant, it’s a part of the overall argument. Well, yes, it is necessary to establish that portion of the argument for a full demonstration of the truth of your claims. The problem is that this had nothing to do with the comment to which you were replying, which concerned whether the difference in mean IQ is due to unobserved confounding. No one doubts that if you took the average IQ for Americans with similar skin color to Larry Byrd, and the average IQ for Americans with similar skin color to Magic Johnson, the former quantity would be larger. The issues are (1) whether “Americans with similar skin color to Magic Johnson” provides a useful definition of “race”, and (2) whether the difference is causally due to genetic factors. Citations such as Edwards and Oakland do not materially address (2), except insofar as IQ scores would have to be comparable for discussion to get off the ground in the first place. But discussion has already gotten off the ground, so … ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [September 12, 2011, 3:28pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/349 "2011-09-12T15:28:48Z")
> [@Paranoid\_Randroid](#): > > Consider: we are investigating the determinants of body mass index, the “meaning” of which is undeniably the same for whites and for blacks. We note that blacks have (pulling this out of the air — I don’t recall what the actual stats are) a higher BMI by 0.7 points on average. > > Does this mean that black Americans have an innate, genetic predisposition toward higher BMI? What if — after controlling for education, income, and a host of other socioeconomic variables — we find that the difference disappears? By analogy, your interlocutors are not claiming that BMI measures something different for different populations; they instead claim that the difference in measured BMI is not _built-in_ but rather the result of unobserved confounding. > > Thus a citation showing that (for example) IQ is comparable between populations is entirely irrelevant. I think that I have been pretty clear about this. As I have noted, there are two questions: 1) “Do the score differences represent real (as opposed to nominal) differences in psychometric intelligence?” and 2) “If so, are the differences caused by genetic or environmental factors?” Citations such as the one above indicate that the score differences represent real differences and so are not akin to Flynn effect differences, which probably – as indicated by the lack of measurement invariance across cohorts – represent a mix of both real differences (e.g. due to improved nutrition) and nominal differences (e.g. due to test familiarity). To use your BMI example, it’s as if we showed that the numeric BMI difference was in fact a physiological BMI difference and showed that the secular increase in BMI scores did not – at least wholly – represent a physiological BMI difference. This is relevant because 1) it narrows the scope of the debate and 2) it points out the irrelevance of the Flynn effect to the debate. ---
**Author:** ![Paranoid\_Randroid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/paranoid_randroid/32/18_2.png) [@Paranoid\_Randroid](https://boards.straightdope.com/u/Paranoid_Randroid)\ **Post date:** [September 12, 2011, 4:03pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/350 "2011-09-12T16:03:16Z")
> [@Chuck11](#): > > [T]here are two questions: 1) “Do the score differences represent real (as opposed to nominal) differences in psychometric intelligence?” and 2) "If so, are the differences caused by genetic or environmental factors? But, again, the point of the statement spurring my comment in the first place — “this directly implies that IQ tests don’t accurately measure differences in general intelligence unless you control for a large number of unknown social variables” — was _not_ that IQ measures are not strictly comparable. (Correct interpretation of the Flynn effect is a side issue.) **Gorsnak** will have to speak for himself, but I don’t understand his statement to cast doubt on the fact that, if we drew two random individuals from the population and compared their IQ scores, the person with a higher score would be more intelligent. The salient point is rather the contention that we must “control for a large number of unknown social variables” in order to discern an accurate measure of “differences in general intelligence.” A naïve comparison of means may not indicate a _strictly causal_ interpretation of the effect of race, if the true problem is that one’s empirical model describing IQ scores is insufficiently rich to capture the true nature of the differences. You can show that IQ scores are comparable; that is a precursor to making your argument. But it is not the argument as a whole nor is it — at least I contend — the interesting _portion_ of your argument. Frankly I think you’re focusing far too much on your question (1); it simply won’t matter that IQ differences “represent real differences” if the difference goes away when controlling for the correct socioeconomic variables. > [@](#): > > it’s as if we showed that the numeric BMI difference was in fact a physiological BMI difference and showed that the secular increase in BMI scores did not – at least wholly – represent a physiological BMI difference I’m not at all sure how to parse that. The point of my example was to demonstrate that showing that IQ scores are comparable is only the first step. The numeric BMI difference just _will be_ a physiological BMI difference, so long as differences in height and weight are physiological; at issue is the question of causes. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [September 12, 2011, 4:07pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/351 "2011-09-12T16:07:25Z")
> [@Paranoid\_Randroid](#): > > Citations such as Edwards and Oakland do not materially address (2), except insofar as IQ scores would have to be comparable for discussion to get off the ground in the first place. But discussion has already gotten off the ground, so … Agreed. But I was responding to this claim: > [@](#): > > Belowjob2.0 > Join Date: Mar 2003 > Quote:Ok, so you agree that within-groups the difference is largely due to genetics – as opposed to education? > > Can’t be true. The Flynn effect has happened too rapidly to be due to genetics. The suggestion was that IQ differences within populations could not be due to genetics because there has been a rapid rise in IQ scores. I was trying to explain why this was a fallacious interpretation. To do that I tried to make a distinction between comparable differences and incomparable (or not readily comparable) differences. My point was that the Black-White difference is comparable to the within Black, within White difference and that the between cohort difference is not. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [September 12, 2011, 4:24pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/352 "2011-09-12T16:24:48Z")
> [@Paranoid\_Randroid](#): > > But, again, the point of the statement spurring my comment in the first place — “this directly implies that IQ tests don’t accurately measure differences in general intelligence unless you control for a large number of unknown social variables” — was _not_ that IQ measures are not strictly comparable. (Correct interpretation of the Flynn effect is a side issue.) **Gorsnak** will have to speak for himself, but I don’t understand his statement to cast doubt on the fact that, if we drew two random individuals from the population and compared their IQ scores, the person with a higher score would be more intelligent. > > The salient point is rather the contention that we must “control for a large number of unknown social variables” in order to discern an accurate measure of “differences in general intelligence.” A naïve comparison of means may not indicate a _strictly causal_ interpretation of the effect of race, if the true problem is that one’s empirical model describing IQ scores is insufficiently rich to capture the true nature of the differences. Ok. So BelowJob said that differences within populations could not be due to genetics. I tried to show that this was a fallacious interpretation. Then Gorsnak said that social variables needed to be controlled for. I interpreted this to mean ‘controlled for, for differences between populations to be real.’ I tried to show that this was not the case. I wasn’t making a claim about the origin of the differences; I was making a claim about the psychometric nature of them. ---
**Author:** ![Sine](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Sine](https://boards.straightdope.com/u/Sine)\ **Post date:** [November 28, 2013, 7:46pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/353 "2013-11-28T19:46:23Z")
> [@OscarGold](#): > > [http://www.nytimes.com/2011/08/28/nyregion/a-fire-department-under-pressure-to-diversify.html](http://www.nytimes.com/2011/08/28/nyregion/a-fire-department-under-pressure-to-diversify.html) > > ^ Consider this story, the operating assumption is that environmental factors are the primary reasons why blacks do poorly on exams (in this case, a firefighter’s exam.) > > Isn’t it ridiculous that in examining why blacks do poorly on IQ test (and other exams which are mostly IQ test by proxy) no one even _CONSIDERS_ the possibility that it’s genetics? > > Black genetics do not produce as many high iq individuals as whites. This seems to me a very plausible explanation of why the high achievers and most interesting individuals in the world are white. > > It’s not something that can proven beyond a reasonable doubt, but it’s pretty convincing. You are obviously not aware that Africans outperform all ethnicities in Western schools and tend to go farther to garner a degree more often. (Put that Asian stereotype down). You are also unaware of Africans/Blacks leading the world in many sciences, political positions (two obvious ones) or that there are Black countries that are not poor and are even on a rapid growth course. You can be forgiven for this as I assume we’re both American. Being from a very “Huxtable” like family it kills me when in Maine one intellectually-challenge classmate asked me How I ‘made it’ out the ghetto. She was actually perplexed that I was from a Black well-to-do neighborhood. You may not be that girl but you guys are in the same class. IQ tests, firefighter and the like frequently are not within the experiences of certain people and thus generally inaccurate. Quantifying intelligence is not exact and possibly never will be. When you are actually are aware instead of assuming from American Media you will make much fewer statements such as these based on race “experts” who got extremely angry when Diop proved the high melanin content of the Pharaohs for the majority of their reign, and even were pissed at Frank Lucas for not being under the Mob. Your welcome. ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [November 28, 2013, 8:39pm UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/354 "2013-11-28T20:39:41Z")
**Sine** , you are addressing a poster who was banned and cannot reply. This conversation that you’ve dug up ended over two years ago. If this topic interests you, I suggest starting a new thread so that we can have a fresh discussion. ---
**Author:** ![bobot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bobot/32/21622_2.png) [@bobot](https://boards.straightdope.com/u/bobot)\ **Post date:** [November 29, 2013, 2:35am UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/355 "2013-11-29T02:35:16Z")
A fresh discussion about race, genetics, and I.Q…NOOOOOoooooooooooooo!:o ---
**Author:** ![Jonathan\_Chance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jonathan_chance/32/701_2.png) [@Jonathan\_Chance](https://boards.straightdope.com/u/Jonathan_Chance)\ **Post date:** [November 29, 2013, 5:14am UTC](https://boards.straightdope.com/t/statistically-blacks-score-poorly-on-iq-and-iq-proxy-exams-than-whites-is-black-genetics-to-blame/594488/356 "2013-11-29T05:14:59Z")
Exactly…no. [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=17)