# 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:** 2
**Author:** ![magnusblitz](https://avatars.discourse-cdn.com/v4/letter/m/b4bc9f/32.png) [@magnusblitz](https://boards.straightdope.com/u/magnusblitz)\ **Post date:** [July 1, 2012, 8:02am UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/21 "2012-07-01T08:02:14Z")
> [@Trinopus](#): > > But income levels, and education levels, are also highly heritable. If your papa was rich, or well-educated, it’s far more likely that you will be. And wealth and education are highly correlated with IQ test scores. > > Kids who grow up with lots of books in the house will be “smarter” than kids who grow up without lots of books in the house. > > The fact that poverty, in the U.S., is also highly correlated to race leads to the fallacy of correlation. “Two things correlated to the same thing may or may not be correlated to each other.” > > Have IQ studies been conducted among sub-populations normalized for education, family wealth, family health, and other social advantages? This would be one of my two hypotheses, the other being what **Der Trihs** mentioned, namely that IQ is not necessarily an unbiased be-all end-all test of “intelligence”, and that the test itself might be biased towards certain race groups. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [July 1, 2012, 8:23am UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/22 "2012-07-01T08:23:11Z")
> [@Trinopus](#): > > But income levels, and education levels, are also highly heritable. If your papa was rich, or well-educated, it’s far more likely that you will be. And wealth and education are highly correlated with IQ test scores. > > Kids who grow up with lots of books in the house will be “smarter” than kids who grow up without lots of books in the house. > > The fact that poverty, in the U.S., is also highly correlated to race leads to the fallacy of correlation. “Two things correlated to the same thing may or may not be correlated to each other.” The heritability of income and education is modest, not high: > [@](#): > > Genotypes may influence the phenotypic associations among IQ, education, and income. To investigate this hypothesis, we believe that the appropriate methodology requires estimation of genetic and environmental influences using data able to separate these influences. The National Longitudinal Survey of Youth (NLSY) is a nationally representative sample that contains genetically-informative full- and half-siblings (28± 35 years old in 1992; Ns = 1943 full-siblings, 129 half siblings). A biometric genetic model was fit that estimated the shared environmental and genetic variance components of IQ, years of education, and hourly income. The total heritabilities were 0.64 for IQ, 0.68 for education, and 0.42 for income. Heritabilities due to a common genetic factor were 0.35 for IQ, 0.52 for education, and 0.12 for income. Environmental influences due to a common shared environmental factor were 0.23 for IQ, 0.18 for education, and 0.08 for income. The model predicted a correlation of 0.63 between IQ and education and 0.34 between IQ and income. Sixty-eight percent of the former and 59% of the latter was genetically mediated; the remainder was mediated by common shared environment. These findings suggest that social inequality in the United States has its origin in both genetically-based traits and in different environmental backgrounds. ([Environmental Influences on IQ, Education, and Income](http://www.uam.es/personal_pdi/psicologia/pei/download/Rowe1999.pdf)) > [@](#): > > Have IQ studies been conducted among sub-populations normalized for education, family wealth, family health, and other social advantages? Yes, this was discussed. The IQ gap increases with parental SES. Controlling for home environmental influences can statistically explain by adulthood 1/3rd of the gap. At younger ages these influences explain more. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [July 1, 2012, 8:35am UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/23 "2012-07-01T08:35:52Z")
> [@magnusblitz](#): > > This would be one of my two hypotheses, the other being what **Der Trihs** mentioned, namely that IQ is not necessarily an unbiased be-all end-all test of “intelligence”, and that the test itself might be biased towards certain race groups. No one is arguing that IQ tests are perfect measures of general intelligence. But the magnitude of the gap correlates with general intelligence, so the imperfection _attenuates_ the size of the differences. That is, on a perfect measure, the gap would be larger than it’s typically found! As for bias, this has been tested over and over again. Typical findings on a tests in which a 1 SD differences is found (which, mind you, is about the magnitude of the difference between random individuals): Edwards and Oakland (2006) [Factorial Invariance of Woodcock-Johnson III Scores for African Americans and Caucasian Americans](https://lesacreduprintemps19.files.wordpress.com/2012/05/factoriial-invariance-woody.pdf) ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [July 1, 2012, 8:41am UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/24 "2012-07-01T08:41:30Z")
> [@Chuck11](#): > > As for bias, this has been tested over and over again. And for decade after decade, bias and outright fraud have been the norm with such claims. I have no interest in indulging the malignant fantasies of racists. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [July 1, 2012, 8:57am UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/25 "2012-07-01T08:57:34Z")
> [@Der\_Trihs](#): > > That IQ tests don’t test for intelligence; that there probably isn’t a single unitary “intelligence” in the first place, that race is a social construct, everything that **Trinopus** said, and that the kind of “scientists” who produce studies with results that claim racial differences in intelligence have a history of being liars, incompetents, or self-deluded. Look, you can check the research for yourself. It’s rock solid when it comes to the [predictive validity of IQ](http://www.unc.edu/~nielsen/soci708/cdocs/Schmidt_Hunter_2004.pdf) (within and between races), [the neurology of general intelligence](http://www.larspenke.eu/pdfs/Deary_Penke_Johnson_2010_-_Neuroscience_of_intelligence_review.pdf) (mostly within races), the [genetic architecture of general intelligence](http://www.lscp.net/persons/ramus/fr/GDP1/papers/Davies11.pdf) (within populations), and group differences in g. As for the latter, typical finding: > [@](#): > > [ETHNIC GROUP DIFFERENCES IN COGNITIVE ABILITY IN EMPLOYMENT AND EDUCATIONAL SETTINGS: A META-ANALYSIS](http://onlinelibrary.wiley.com/doi/10.1111/j.1744-6570.2001.tb00094.x/abstract) > > The cognitive ability levels of different ethnic groups have interested psychologists for over a century. Many narrative reviews of the empirical literature in the area focus on the Black-White differences, and the reviews conclude that the mean difference in cognitive ability (g) is approximately 1 standard deviation; that is, the generally accepted effect size is about 1.0. We conduct a meta-analytic review that suggests that the one standard deviation effect size accurately summarizes Black-White differences for college application tests (e.g., SAT) and overall analyses of tests of g for job applicants in corporate settings. However, the 1 standard deviation summary of group differences fails to capture many of the complexities in estimating ethnic group differences in employment settings. For example, our results indicate that job complexity, the use of within job versus across job study design, focus on applicant versus incumbent samples, and the exact construct of interest are important moderators of standardized group differences. In many instances, standardized group differences are less than 1 standard deviation. We conduct similar analyses for Hispanics, when possible, and note that Hispanic-White differences are somewhat less than Black-White differences. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [July 1, 2012, 9:00am UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/26 "2012-07-01T09:00:14Z")
> [@Der\_Trihs](#): > > I have no interest in indulging the malignant fantasies of racists. Good. Then don’t comment here. ---
**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:** [July 1, 2012, 9:13am UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/27 "2012-07-01T09:13:43Z")
> [@Chuck11](#): > > Good. Then don’t comment here. 🙂 ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [July 1, 2012, 9:18am UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/28 "2012-07-01T09:18:29Z")
> [@Chuck11](#): > > Good. Then don’t comment here. As a “gotcha” that’s a complete failure. ---
**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:** [July 1, 2012, 9:42am UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/29 "2012-07-01T09:42:00Z")
> [@Der\_Trihs](#): > > As a “gotcha” that’s a complete failure. I thought it was rather successful myself. 🆒 ---
**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:** [July 1, 2012, 9:43am UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/30 "2012-07-01T09:43:39Z")
> [@Der\_Trihs](#): > > And for decade after decade, bias and outright fraud have been the norm with such claims. An assertion like that requires credible documentation. ---
**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:** [July 1, 2012, 9:53am UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/31 "2012-07-01T09:53:18Z")
> [@Der\_Trihs](#): > > I have no interest in indulging the malignant fantasies of racists. Translated from Latin to English, “Ad Hominem” means “against the man” or “against the person.” An Ad Hominem is a general category of fallacies in which a claim or argument is rejected on the basis of some irrelevant fact about the author of or the person presenting the claim or argument. Typically, this fallacy involves two steps. First, an attack against the character of person making the claim, her circumstances, or her actions is made (or the character, circumstances, or actions of the person reporting the claim). Second, this attack is taken to be evidence against the claim or argument the person in question is making (or presenting). This type of “argument” has the following form: Person A makes claim X. Person B makes an attack on person A. Therefore A’s claim is false. The reason why an Ad Hominem (of any kind) is a fallacy is that the character, circumstances, or actions of a person do not (in most cases) have a bearing on the truth or falsity of the claim being made (or the quality of the argument being made). [http://www.nizkor.org/features/fallacies/ad-hominem.html](http://www.nizkor.org/features/fallacies/ad-hominem.html) * * * Description of Appeal to Emotion An Appeal to Emotion is a fallacy with the following structure: Favorable emotions are associated with X. Therefore, X is true. This fallacy is committed when someone manipulates peoples’ emotions in order to get them to accept a claim as being true. More formally, this sort of “reasoning” involves the substitution of various means of producing strong emotions in place of evidence for a claim. [http://www.nizkor.org/features/fallacies/appeal-to-emotion.html](http://www.nizkor.org/features/fallacies/appeal-to-emotion.html) * * * Description of Appeal to Ridicule The Appeal to Ridicule is a fallacy in which ridicule or mockery is substituted for evidence in an “argument.” This line of “reasoning” has the following form: X, which is some form of ridicule is presented (typically directed at the claim). Therefore claim C is false. This sort of “reasoning” is fallacious because mocking a claim does not show that it is false. [http://www.nizkor.org/features/fallacies/appeal-to-ridicule.html](http://www.nizkor.org/features/fallacies/appeal-to-ridicule.html) * * * Description of Personal Attack A personal attack is committed when a person substitutes abusive remarks for evidence when attacking another person’s claim or claims. This line of “reasoning” is fallacious because the attack is directed at the person making the claim and not the claim itself. The truth value of a claim is independent of the person making the claim. [http://www.nizkor.org/features/fallacies/personal-attack.html](http://www.nizkor.org/features/fallacies/personal-attack.html) * * * Der Trihs, As soon as you call someone a “racist” you have lost the argument. What matters is not whether or not you think someone is a “racist,” but whether or not the person’s assertions are true. ---
**Author:** ![tomndebb](https://avatars.discourse-cdn.com/v4/letter/t/b9e5f3/32.png) [@tomndebb](https://boards.straightdope.com/u/tomndebb)\ **Post date:** [July 1, 2012, 10:04am UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/32 "2012-07-01T10:04:12Z")
I am about to close this thread and isue Warnings to a whole bunch of posters. All the nasty comments directed to other posters regarding their intelligence, racism, etc., and all the snide and smug claims of one’s own superior position are now off limits in this thread. Stick to arguing facts and leave ALL the personal commentary out of this thread. [/Moderating] ---
**Author:** ![gamerunknown](https://avatars.discourse-cdn.com/v4/letter/g/6bbea6/32.png) [@gamerunknown](https://boards.straightdope.com/u/gamerunknown)\ **Post date:** [July 1, 2012, 12:07pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/33 "2012-07-01T12:07:26Z")
Religion and political affiliation are far more heritable than intelligence. ---
**Author:** ![Belowjob2.0](https://avatars.discourse-cdn.com/v4/letter/b/b9e5f3/32.png) [@Belowjob2.0](https://boards.straightdope.com/u/Belowjob2.0)\ **Post date:** [July 1, 2012, 1:38pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/34 "2012-07-01T13:38:48Z")
> [@Chuck11](#): > > Ibn Warraq, are you a negroid? Will you be my friend? 😉 So, is this [intellectual rape](http://boards.straightdope.com/sdmb/showpost.php?p=15224900&postcount=100), or are you just cruising for rough trade? ---
**Author:** ![RickJay](https://avatars.discourse-cdn.com/v4/letter/r/bb73d2/32.png) [@RickJay](https://boards.straightdope.com/u/RickJay)\ **Post date:** [July 1, 2012, 2:18pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/35 "2012-07-01T14:18:36Z")
> [@Ibn\_Warraq](#): > > No, it is not “well know(sic) that there’s a Black(sic)-White(sic) racial difference(sic) in intelligence.” Just before the thread gets closed, an additional point; **MODERATING** Never, ever change the content of another poster’s post inside the quote function, for any reason. (which you did, but I am not referring to the quote above; I mean the point in your post where you used the quote tag function to write the same thing.) That is a warning offense. I will leave it to **tomndebb** to decide if you should get a formal warning for it, but do NOT do it again, in any forum. RickJay Moderator ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [July 1, 2012, 5:49pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/36 "2012-07-01T17:49:03Z")
> [@Chuck11](#): > > Good. Then don’t comment here. You neither. And start no more GD threads. Go to [the Pit](http://boards.straightdope.com/sdmb/showthread.php?t=653465) and stay there forever, please. ---
**Author:** ![Chuck11](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Chuck11](https://boards.straightdope.com/u/Chuck11)\ **Post date:** [July 1, 2012, 6:28pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/37 "2012-07-01T18:28:53Z")
> [@gamerunknown](#): > > Religion and political affiliation are far more heritable than intelligence. No not really. Refer here: [Genetic influences on human psychological traits: A survey](http://www18.homepage.villanova.edu/diego.fernandezduque/Teaching/PhysiologicalPsychology/zCurrDir4200/CurrDirGeneticsTraits.pdf) The h^2 of religiousness is .3-.45 by adulthood; as one would expect, the h^2 of specific affiliations is 0. See table 1. Political orientation has a modest heritability. You can check the [quantitative genetic results here](http://www.pnas.org/content/early/2012/05/02/1120666109.abstract). The broad heritability of intelligence is typically estimated to be about .7. Some argue that this includes active GE covariance (i.e., individuals seeking out cognitive niches corresponding to their dispositions). ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [July 1, 2012, 8:16pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/38 "2012-07-01T20:16:43Z")
Out of sheer bloody-minded sake-of-argument curiosity, let’s assume the answer is “yes”. What should we _do_ with this knowledge? ---
**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:** [July 1, 2012, 8:29pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/39 "2012-07-01T20:29:55Z")
> [@Bryan\_Ekers](#): > > Out of sheer bloody-minded sake-of-argument curiosity, let’s assume the answer is “yes”. > > What should we _do_ with this knowledge? We should continue to move in the directions we are moving in. We should put an end to forced school busing, affirmative action, and Aid to Families with Dependent Children. We should institute free abortion on demand. That is the only welfare program I have any enthusiasm for. We should continue to expand the prison population. We should put more criminals in prison longer and treat them more harshly. The reason we are moving in these directions is that the voters are intuitively aware that what Charles Murray and others like him say is correct, even though most have probably not heard of them. There are few things stronger than an ideal whose time has come. ---
**Author:** ![Shoujin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoujin/32/3884_2.png) [@Shoujin](https://boards.straightdope.com/u/Shoujin)\ **Post date:** [July 1, 2012, 9:09pm UTC](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877/40 "2012-07-01T21:09:36Z")
Apologies, but IMHO that sounds to me like a slippery slope to ethnic cleansing. That’s not what you’re leading to, I hope. [Previous page](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877.md?page=1) [Next page](https://boards.straightdope.com/t/can-the-black-white-racial-iq-gap-in-the-us-be-environmentally-explained/626877.md?page=3)