A Different View of the Minnesota Transracial Adoption Study

I would emphasize somewhat different aspects of the Minnesota Transracial Adoption Study than does Richard Lynn.

For one thing, it seems premature to assert with certainty that the intelligence of the American populace has been rising at the rate of 3 IQ points per decade. The people who built America in the 19th century could hardly have been mainly retardates. Perhaps intelligence has remained constant and more recent IQ tests have measured it more accurately.

What matters is that the Scarr study is independent of changes in IQ tests, since all the adopted children as well as the biological children (birth children) of the white adoptive parents took the same IQ tests. Environmentalism predicts that by late adolescence the IQs of the black adopted children would approach those of the birth children, or at least those of the white adopted children. This did not happen.

Even if the average IQ score of 89 for the black children raised in a white environment (the score reported in the follow-up test) represents a real gain over the national black average of 85, this gain is much smaller than would have been expected if the race gap is wholly environmental in origin. The crucial point is that the gap between the average IQs of the black and white adopted children is as large as that between blacks and whites in the general population. Though Prof. Lynn does not mention the IQ scores of the birth children, the gap between their scores and those of the black adopted children is even wider.

I think it is possible that being reared in a white environment may have somewhat increased the IQ scores of adopted black children. A little-mentioned factor of great importance in interpreting the Scarr study is the high quality of the adoptive white environments. The typical father, for example, had some education at the post-graduate level. In other words, although the adoptive environments were unusually rich even by white standards, the IQs of the black adopted children increased only a few points (if at all), and remained far below the national white average. In a commentary on the Scarr study scheduled to appear along with Prof. Lynn’s in the journal Intelligence, I therefore estimate that the race gap in IQ would remain about 85 percent of what it is now even if blacks were raised in the typical white environment.

Incidentally, a phenomenon called “gene/environment correlation” explains how a rich environment can have some effect on black intelligence even if 100 percent of the race difference in intelligence is ultimately due to genetic factors. One of the ways genes produce high IQs is by producing high-quality environments, which in turn stimulate the development of children raised in them. Smart parents speak intelligently to their genetically smart children, which makes their children even smarter. So it would not be surprising if the high-quality environments in the Scarr study gave black children a few extra points of IQ; the catch, for the environmentalist, is that these environments themselves were created by white people in accordance with their distinctive genetic endowments.

The second matter on which I would take a somewhat different tack from Prof. Lynn is his “policy consequences.” Right now, the white majority in the United States is wholly unprepared to take any steps adverse to black interests, such as limiting immigration from black countries. What is much more important at the moment is that whites understand the calumnious charges constantly being hurled against them and be ready to assert their innocence. The great moral of the Scarr study is that blacks really are far less intelligent than whites, and they are so for genetic reasons that whites had nothing to do with. When “white racism” is said to keep blacks from succeeding in prestigious and remunerative professions, whites can now reply, “Not guilty.” After they have become confident in this unaccustomed reply, they can go on to think about repairing their country.