# Can the Black-White racial IQ gap in the US be environmentally explained? **URL:** \ **Category:** Great Debates\ **Created:** [July 1, 2012, 4:56am UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877 "2012-07-01T04:56:56Z")\ **Posts on this page:** 20\ **Page:** 12
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [July 13, 2012, 8:43pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/221 "2012-07-13T20:43:46Z")
> [@Evil\_Economist](#): > > Everything you said above is wrong. > > Do you know what statistically insignificant means? In this case it means those numbers cannot be distinguished from zero. Au contraire! Nothing I said was in error. (a) I referred to the calculations made by Scarr et al.,: “An extrapolation from the contrast between extremes within the hybrid group to the average differences between the races predicts that not more than one third of the observed difference between the races could be due to genetic differences. In view of the negligible correlations between estimated ancestry and intellectual skills even this seems unlikely" (b) I pointed out that the conclusion drawn was incorrect – there was nothing original here as all of this has already been said – and (c) I showed that the found correlations were utterly consistent with a genetic hypothesis – again nothing original here, which is just to say – which should be obvious – that the study lacked the power to detect a statistically significant difference, given the magnitude of possible difference under discussion, the sample size, and the methodology. That is, there was a type II error here. To put it yet another way, since you seem to be having trouble with this, if the correlation found (-.05) was found to be stat sig. – which would have required approximately 4000 subjects in the study – then we could be reasonably sure that the genetic component of the difference was well over 50%. The point then was that the findings of this study were not inconsistent with the genetic hypothesis under question. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [July 13, 2012, 8:56pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/222 "2012-07-13T20:56:15Z")
> [@MrDibble](#): > > Dude, 338 Google hits is basically non-existent, considering more than 75% of those hits are referring to completely unrelated stuff like actual footraces or just spamming word aggregations. So do you or do you not grant the distinction between race as zoologically defined and race as [other-wisely defined in biology](http://en.wikipedia.org/wiki/Ecotype)? Or would you argue that all biologically defined race concepts are identical to the concept used in zoology? ---
**Author:** ![Evil\_Economist](https://avatars.discourse-cdn.com/v4/letter/e/c89c15/32.png) [@Evil\_Economist](https://boards.straightdope.com/u/Evil_Economist)\ **Post date:** [July 13, 2012, 9:00pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/223 "2012-07-13T21:00:22Z")
> [@Chuck11](#): > > Au contraire! Nothing I said was in error. (a) I referred to the calculations made by Scarr et al. I agree that so long as you were quoting Scarr, you were not saying anything wrong. The problems crept in when you started adding your own commentary. > [@](#): > > To put it yet another way, since you seem to be having trouble with this, if the correlation found (-.05) was found to be stat sig. – which would have required approximately 4000 subjects in the study – then we could be reasonably sure that the genetic component of the difference was well over 50%. I’m not the one having a problem here. The correlation found was NOT statistically significant, therefore everything you said was wrong. Do you deny this? Also, you seem to be assuming that if we’d had more subjects in the study, we’d have had the same result but at a higher level of significance. This is of course utterly wrong. > [@](#): > > The point then was that the findings of this study were not inconsistent with the genetic hypothesis under question. This is also utterly wrong. The results of this study could not reject the null hypothesis; that is, they explicitly contradicted the genetic hypothesis. We would expect the correlations to be statistically insignificant if the genetics hypothesis were false, and that’s the result we got. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [July 13, 2012, 9:24pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/224 "2012-07-13T21:24:54Z")
> [@Evil\_Economist](#): > > And yet when I look at your study I see the following: “The author argues that this error nullifies the negative finding of the studies, and leaves open the question of whether definitive tests of the genetic hypothesis are possible.” > > So you’ve quoted a paper stating that it might not be possible to link genetics to IQ at all. Descartes entertained radical skepticism – and rejected it. Would citing him in defense of certain knowledge represent an inconsistency on my part, given his willingness to entertain? Likewise, Reed entertained the possibility that no admixture study could resolve the issue – and rejected it. He then went onto discuss the methodological flaws in the Scarr et al. study and propose an improved method which could be used with a sample size similar to that used by Scarr et al. > [@](#): > > And it’s especially curious that you would quote this paper immediately after trying to calculate the effects of genetics on IQ(while making a bunch of obvious errors). You have contradicted yourself within one post. Again, no contradiction. I showed that the correlation found was consistent with that predicted by a genetic hypothesis, given the methodology used. Reed explained why the methodology used, given the sample size, was unable to detect a stat sig difference. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [July 13, 2012, 9:39pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/225 "2012-07-13T21:39:49Z")
> [@Chuck11](#): > > A google search gives me 338 hits, so I’m not the only one who uses it. Race is a generic term. “Zoological” modifies it. “Zoological race” specifically refers to the race concept in zoology. There are other race concepts in biology, such as ecotype and breeding population. Actually, no. [Ecotype](http://en.wikipedia.org/wiki/Ecotype) is **identical** to what you apparently mean by “zoological race.” And “biological race,” if it means anything different than that, could only be another (and needless) term for “species.” ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [July 13, 2012, 9:41pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/226 "2012-07-13T21:41:26Z")
> [@Chuck11](#): > > So do you or do you not grant the distinction between race as zoologically defined and race as [other-wisely defined in biology](http://en.wikipedia.org/wiki/Ecotype)? Or would you argue that all biologically defined race concepts are identical to the concept used in zoology? Well, what else is there, botany? ---
**Author:** ![Left\_Hand\_of\_Dorkness](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/left_hand_of_dorkness/32/7156_2.png) [@Left\_Hand\_of\_Dorkness](https://boards.straightdope.com/u/Left_Hand_of_Dorkness)\ **Post date:** [July 13, 2012, 9:42pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/227 "2012-07-13T21:42:54Z")
**Chuck** , I wonder if you’d mind running your race theories by the [Yo, Is This Racist?](http://yoisthisracist.com/) blog. He might be able to help you figure it out. ---
**Author:** ![Evil\_Economist](https://avatars.discourse-cdn.com/v4/letter/e/c89c15/32.png) [@Evil\_Economist](https://boards.straightdope.com/u/Evil_Economist)\ **Post date:** [July 13, 2012, 9:50pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/228 "2012-07-13T21:50:12Z")
> [@Chuck11](#): > > Reed entertained the possibility that no admixture study could resolve the issue – and rejected it. He then went onto discuss the methodological flaws in the Scarr et al. study and propose an improved method which could be used with a sample size similar to that used by Scarr et al. I’m sorry, but I’d prefer to read his conclusions for myself; do you have a link to the paper? > [@](#): > > Again, no contradiction. I showed that the correlation found was consistent with that predicted by a genetic hypothesis, given the methodology used. I think you misspoke; you meant to say “The lack of statistical significance was consistent with that predicted by a purely environmental hypothesis, given the methods used” ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [July 13, 2012, 9:51pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/229 "2012-07-13T21:51:03Z")
> [@Evil\_Economist](#): > > This is also utterly wrong. The results of this study could not reject the null hypothesis; that is, they explicitly contradicted the genetic hypothesis. We would expect the correlations to be statistically insignificant if the genetics hypothesis were false, and that’s the result we got. Again, the results did not contradict a genetic hypothesis, because the study lacked the [power](http://en.wikipedia.org/wiki/Statistical_power) to test it. The correlation predicted by a genetic hypothesis is about -.05. I can go through the math if you want. This was the correlation found. Given the sample size, it would have been impossible for this correlation to have been found to be statistically significant. The findings are consistent with a genetic hypothesis in the sense that the correlation found was identical to the correlation predicted. > [@](#): > > I’m not the one having a problem here. The correlation found was NOT statistically significant, therefore everything you said was wrong. Do you deny this? Reread what I said. Nothing was incorrect. My point was twofold: (a) the correlation/ mean difference found was no different from the correlation predicted (b) the study lacked the power to test a genetic hypothesis On the basis of this I argued that the findings were consistent – perhaps I should have said “not inconsistent” – with a genetic hypothesis. They were also, of course, consistent with a environmental hypothesis. Which is to say that they are unable to reduce the genetic-environmental uncertainty. > [@](#): > > Also, you seem to be assuming that if we’d had more subjects in the study, we’d have had the same result but at a higher level of significance. This is of course utterly wrong. “Seem” is a weasel word. I made no such assumption. I merely pointed out that, contra Scarr et al., the magnitude of the correlation was consistent with a genetic hypothesis. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [July 13, 2012, 9:59pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/230 "2012-07-13T21:59:16Z")
> [@Evil\_Economist](#): > > I’m sorry, but I’d prefer to read his conclusions for myself; do you have a link to the paper? > > I think you misspoke; you meant to say “The lack of statistical significance was consistent with that predicted by a purely environmental hypothesis, given the methods used” You can find Reed’s paper online; I did. I don’t have a copy of it on hand. I quoted the relevant sections though. The results are consistent with both an environmental and genetic hypothesis, as explained. I didn’t misspeak. Reread what I said. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [July 13, 2012, 10:07pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/231 "2012-07-13T22:07:19Z")
> [@BrainGlutton](#): > > Well, what else is there, botany? **Biological race concepts** Geographic subspecies = zoology Ecotype = evolutionary ecology Breeding population = population genetics ---
**Author:** ![Evil\_Economist](https://avatars.discourse-cdn.com/v4/letter/e/c89c15/32.png) [@Evil\_Economist](https://boards.straightdope.com/u/Evil_Economist)\ **Post date:** [July 13, 2012, 10:09pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/232 "2012-07-13T22:09:28Z")
> [@Chuck11](#): > > Again, the results did not contradict a genetic hypothesis, because the study lacked the [power](http://en.wikipedia.org/wiki/Statistical_power) to test it. The correlation predicted by a genetic hypothesis is about -.05. I can go through the math if you want. This was the correlation found. Given the sample size, it would have been impossible for this correlation to have been found to be statistically significant. The findings are consistent with a genetic hypothesis in the sense that the correlation found was identical to the correlation predicted. Let’s be very clear here: the statistical correlation found by the study was indistinguishable from zero. You can hypothesize all you like about the results that would have been found if there had been more subjects, but that’s not what was found. You are focused on this -0.05, but this is absolutely incorrect; that number has no significance at all, and by saying both 1) it was statistically insignificant and 2) it was exactly what it should be, you are contradicting yourself. > [@](#): > > Reread what I said. Nothing was incorrect. My point was twofold: > (a) the correlation/ mean difference found was no different from the correlation predicted > (b) the study lacked the power to test a genetic hypothesis > > On the basis of this I argued that the findings were consistent – perhaps I should have said “not inconsistent” – with a genetic hypothesis. They were also, of course, consistent with a environmental hypothesis. Which is to say that they are unable to reduce the genetic-environmental uncertainty. Their findings were consistent \*only \*with the environmental hyopthesis. You can argue that they should have run the test differently, but the results of that study \*ruled out \*the genetic hypothesis. If you think a new test with more subjects would produce different results, then go run that test, but don’t try to mislead anyone by claiming that the results of this test are any different than they were. > [@](#): > > “Seem” is a weasel word. I made no such assumption. I merely pointed out that, contra Scarr et al., the magnitude of the correlation was consistent with a genetic hypothesis. The magnitude of the correlation was statistically indistinguishable from zero, which is consistent only with an environmental hypothesis. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [July 13, 2012, 10:20pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/233 "2012-07-13T22:20:22Z")
> [@BrainGlutton](#): > > Actually, no. [Ecotype](http://en.wikipedia.org/wiki/Ecotype) is **identical** to what you apparently mean by “zoological race.” And “biological race,” if it means anything different than that, could only be another (and needless) term for “species.” Refer to the discussion herein: [http://www.jstor.org/discover/10.1086/377397?uid=3739776&uid=2&uid=4&uid=3739256&sid=21100916414021](http://www.jstor.org/discover/10.1086/377397?uid=3739776&uid=2&uid=4&uid=3739256&sid=21100916414021) They are related but distinct concepts. ---
**Author:** ![Evil\_Economist](https://avatars.discourse-cdn.com/v4/letter/e/c89c15/32.png) [@Evil\_Economist](https://boards.straightdope.com/u/Evil_Economist)\ **Post date:** [July 13, 2012, 10:24pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/234 "2012-07-13T22:24:10Z")
> [@Chuck11](#): > > Refer to the discussion herein: > [http://www.jstor.org/discover/10.1086/377397?uid=3739776&uid=2&uid=4&uid=3739256&sid=21100916414021](http://www.jstor.org/discover/10.1086/377397?uid=3739776&uid=2&uid=4&uid=3739256&sid=21100916414021) > > They are related but distinct concepts. The abstract of that paper says: “human ecotypic races do not in general correspond with ‘folk’ racial categories…consequently while human natural races exist they have little or nothing in common with ‘folk’ races.” Do you realize that you just cited a paper that specifically says there’s no such thing as a black race? ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [July 13, 2012, 10:38pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/235 "2012-07-13T22:38:11Z")
> [@Evil\_Economist](#): > > Their findings were consistent \*only \*with the environmental hyopthesis. You can argue that they should have run the test differently, but the results of that study \*ruled out \*the genetic hypothesis. The magnitude of the correlation was statistically indistinguishable from zero, which is consistent only with an environmental hypothesis. I’ll say this one more time: The study lacked the power to test a genetic hypothesis. It was incapable of ruling in or out a genetic hypothesis. That the magnitude of the found correlation was statistically indistinguishable from that predicted by a genetic hypothesis was consistent with a genetic hypothesis. ---
**Author:** ![Evil\_Economist](https://avatars.discourse-cdn.com/v4/letter/e/c89c15/32.png) [@Evil\_Economist](https://boards.straightdope.com/u/Evil_Economist)\ **Post date:** [July 13, 2012, 10:38pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/236 "2012-07-13T22:38:31Z")
> [@Evil\_Economist](#): > > Let’s be very clear here: the statistical correlation found by the study was indistinguishable from zero. You can hypothesize all you like about the results that would have been found if there had been more subjects, but that’s not what was found. > > You are focused on this -0.05, but this is absolutely incorrect; that number has no significance at all, and by saying both 1) it was statistically insignificant and 2) it was exactly what it should be, you are contradicting yourself. Let me add that upon reading the paper further, the (still significantly insignificant) correlation was actually -0.02. That makes your “analysis” wrong in two ways. ---
**Author:** ![Evil\_Economist](https://avatars.discourse-cdn.com/v4/letter/e/c89c15/32.png) [@Evil\_Economist](https://boards.straightdope.com/u/Evil_Economist)\ **Post date:** [July 13, 2012, 10:47pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/237 "2012-07-13T22:47:49Z")
> [@Chuck11](#): > > I’ll say this one more time: The study lacked the power to test a genetic hypothesis. It was incapable of ruling in or out a genetic hypothesis. That the magnitude of the found correlation was statistically indistinguishable from that predicted by a genetic hypothesis was consistent with a genetic hypothesis. You know, I Google searched some of your posts here. You post word-for-word stuff in lots of places across the internet. Lots of discussions of race IQ differences using exactly the same language you used here, even the same typos. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [July 13, 2012, 10:51pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/238 "2012-07-13T22:51:41Z")
> [@Evil\_Economist](#): > > The abstract of that paper says: “human ecotypic races do not in general correspond with ‘folk’ racial categories…consequently while human natural races exist they have little or nothing in common with ‘folk’ races.” > > Do you realize that you just cited a paper that specifically says there’s no such thing as a black race? They argue – and I disagree with them on this point --that the classic racial delineations don’t match “natural races.” And – and I agree with them on this point – that there are natural races, delineated otherwise. Again no contradiction. Since my original point was “the non existence of zoological races wouldn’t imply the non existence of biological races other-wisely defined.” As for “black races” they might exist from an ecotypic perspective. . ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [July 13, 2012, 10:55pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/239 "2012-07-13T22:55:09Z")
> [@Evil\_Economist](#): > > Let me add that upon reading the paper further, the (still significantly insignificant) correlation was actually -0.02. That makes your “analysis” wrong in two ways. You misread the study then. The -.02 is after controlling for skin color. Which controls for ancestry. That’s a form of the sociologist fallacy, ---
**Author:** ![Evil\_Economist](https://avatars.discourse-cdn.com/v4/letter/e/c89c15/32.png) [@Evil\_Economist](https://boards.straightdope.com/u/Evil_Economist)\ **Post date:** [July 13, 2012, 10:57pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/240 "2012-07-13T22:57:31Z")
> [@Chuck11](#): > > They argue – and I disagree with them on this point --that the classic racial delineations don’t match “natural races.” Well, they have a published, peer-reviewed paper to support their argument. You don’t. > [@](#): > > As for “black races” they might exist from an ecotypic perspective. . Yeah, except you’re citing evidence that they don’t. By the way, you never answered the question re: the NPI. You said you agree with their position. so, are you a white supremacist? [Previous page](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877.md?page=11) [Next page](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877.md?page=13)