http://www.gnxp.com/MT2/archives/004064.html
I won't be discussing the obvious mental abilities of South Asian-Americans due to their relative newness and unusual selectivity, but, as seen in Scott's post below, a frequently raised explanation for why American ethnic groups differ in performance, such as why East Asian-Americans score higher than white Americans in academics and on IQ tests, and also why African-Americans score lower, is that the differences are due to different cultural values (Warren Bell and Jonah Goldberg also raised the culture objection over at National Review to Cochran and Harpending's Ashkenazi paper). There are a number of reasons to doubt this. For one, the sociological literature doesn't seem to show it. As Stanley Sue and Sumie Okazaki pointed out in their 1991 American Psychologist paper, Asian American Educational Achievements: A Phenomenon in Search of an Explanation, the parenting styles and values found in East Asian-American homes tend to correlate with lower test scores when they are found in white homes. Further, even according to what we see in Roland Fryer's newest paper on "acting white", the idea that blacks have a culture of lower academic values, which is increasingly being embraced by liberals thanks to John Ogbu, is at least highly exaggerated and simply cannot account for the IQ gap. In fact, despite their lower performance, which is genuine, multiple lines of evidence point to African-Americans valuing academics nearly as much as white Americans, if not equally so (for instance spending just as much time on homework. A number of lines of evidence are discussed by Ludwig and Cook in The Black-White Test Score Gap, which you can read here). But an even more profound revelation that causes doubt about cultural explanations is that behavioral genetic experiments show us that home and parental environments don't seem to matter at all. As fantastic as it may be, at least three big studies now show us that unrelated children raised in the same household, as well as parents and their adoptive children, differ in IQ as much as any two strangers randomly picked from the general population. There are IQ similarities in biological families, but we find that once genes are accounted for, there is no residual left to explain.
So there are many good reasons to doubt cultural explanations a priori, but a more direct test is available. One possible way to control for distinct ethnic values is simply to raise the children of higher or lower scoring racial backgrounds in another ethnocultural environment of purportedly different values. If ethnic differences are caused by ethnically different parents, as asserted by gene-disparaging psychologists such as Richard Nisbett, then such a test should settle the issue. The transracial adoption data we have so far doesn't appear to support Nisbett.
One longitudinal study, the only one of its kind, of black children raised in white homes, showed that by highschool these adoptees scored no differently on IQ tests than African-Americans raised by their biological parents. Meanwhile three studies of Asians [1] raised in white families showed higher than average test scores. A problem with these latter three papers of Asian adoptees is that they didn't use control samples of white adoptees. Did the Asian children just score higher because adoptees in general score higher?
A newer study published in the American Journal of Orthopsyciatry allows us to compare adopted white children with, at least small samples of, transracially adopted Asian children to try and answer this question. An advantage of this study is that it used data from the National Longitudinal Study of Adolescent Health which means it was able to compare developmentally mature adoptees in grades 7-12, instead of children at ages like 4 or 6 when differences are less stable. Comparing 350 white adoptees with 24 Asian transracial adoptees, and (a mere) 8 black transracial adoptees, the authors found differences on a number of different dimensions that went in the same direction they usually do, despite the controlled ethnic upbringing (lower scores mean better grades, less learning problems, less delinquency, and more self-esteem):
++++++++++++++++++++Asian Adoptees+++White Adoptees++Black Adoptees
Grades+++++++++++++++1.72 (A-)+++++++++++2.25 (B+)+++++++++2.67 (B-)
Learning problems+++++++1.06++++++++++++++1.12+++++++++++++1.34
Delinquency++++++++++++0.16+++++++++++++0.20++++++++++++++0.25
Self-esteem++++++++++++2.07+++++++++++++1.96++++++++++++++1.78
The small sample sizes cry out for a larger replication (along with the Scarr adoption study which only had 21 black children, but had the advantage of an additional 55 black-white mixed race children who fell in between the white and black children on all academic variables), and other aspects of this study are not compatible with other published studies (i.e. contrary to the Moore study, also used as cultural evidence by Nisbett, it also showed that adopted black children raised in black households performed similarly, even somewhat better than, the transracially adopted black children in this study). But still the differing levels of performance of the transracially adopted black and Asian in this study are compatible with other adoption experiments which show similar results, and casts further doubt on the theory that ethnic differences are due to differences in upbringing unique to separate American ethnic groups (further evidence for this was also demonstrated with another method by Rowe and Flannery who found no unique correlation patterns in the developmental data of different ethnic groups).
The Results showing higher grades for the Asian adoptees is particularly interesting, becuase of the control of white adoptees unique to this study. If Asian academic success was really due to some special set of academic values inculcated by Asian parents (something not demonstrated by the data to begin with), then why do Asians do better academically than whites even when they are raised by white parents? The authors of this paper contend the Asians might have done better academically because the parents may have believed Asians had genetically higher IQs and therefore had higher expectations for them. The authors provide no evidence for this idea except the adopted Asian children's own greater optimism about their academic futures! Quite the tenuous conclusion to take from that fact, but even allowing their interpretation, given that behavior genetic evidence shows that such parental attitudes have no effect on children's scores, there is good reason to doubt this ad-hoc attempt to squeeze cultural rationalizations even into ethnically controlled data. It would be incorrect though to say this matter has been resolved.
Update 06/12/05
I was curious how the adoption data from the new study compares with the high-school grade-point averages (GPAs) of Asians, whites, and blacks in the general population, so I compared it with this data from the National Assessment of Educational Progress (NAEP). Since the gaps fluctuate somewhat year to year I averaged the data from 1990, 1994, 1998, and 2000 (It's only high-school graduates, so the gaps should be a little reduced). I wasn't interested in the absolute scores but the differences between ethnic groups, which I've listed below.
Adoption............................................General
Asian-White: 33 points........................Asian-White: 15 points
White-Black: 42 points........................White-Black: 36 points
Black-Asian: 75 points........................Black-Asian: 51 points
The gaps are surprisingly similar! Contrary to "culture" theory, the ethnic academic gaps are almost identical for transracially adopted children, and to the extent they are different they go in the opposite direction predicted by culture theory. The gap between whites and Asians fluctuated from 19 to .09 in the NAEP data while the gap in the adoption data is from 1/3 to 3 times larger. This is consistent with the Sue and Okazaki paper above which showed that contrary to popular anecdotes, the values that lead to higher academic grades are actually found more often in white homes. In other words Asian-Americans perform highly despite their Asian home cultural environment not because of it. And though the sample is meager, I find it interesting that the gap between the black and white adopted children was virtually identical (within just 4-6 points) to the gap between whites and blacks in the general population, just like in the Scarr adoption study.
[1] Clark, E. A., & Hanisee, J. (1982). Intellectual and adaptive
performance of Asian children in adoptive American settings.
Developmental Psychology, 18, 595–599.
Frydman, M., & Lynn, R. (1989). The intelligence of Korean children
adopted in Belgium. Personality and Individual Differences, 12, 1323–1325.
Winick, M., Meyer, K. K., & Harris, R. C. (1975). Malnutrition and
environmental enrichment by early adoption. Science, 190, 1173–1175.
The Scarr study also had a small sample of "Asians", but on closer examination a large percentage of them were actually absurdly labeled Native Americans! Amerindians are only "Asians" in the sense that we are all "Africans". The "Asians" in her study unsurprisingly did not score very high.
