Black People and White People: Differences in Intelligence

The most inflamed arguments about the heritabiiity   of IQ have involved the fact that, in the United States, black people on average tend to score some 10 to 15 points lower in IQ than do white people. This fact has been known for a long time. The Army testing program of World War I indicated such a difference-and it also indicated that black people in some northern states had a higher average IQ than whites in some southern states. To some the data proclaimed that black people were genetically inferior to white people, To others the data indicated   that IQ was determined by educational and environmental opportunities.

The influential article by Jensen (1969) already cited, not only argued that the heritability of IQ among white people was .80, but it also maintained that the difference in average IQ between black people and white people was probably of genetic origin. Further in Jensen's view, attempts at compensatory education of underprivileged children-such programs as Head Start and other interventions aimed at increasing the children's intellectual competence-had failed, arid were bound to fail. That was so, said Jensen, because of the high heritability of IQ. Since then, of course, the effectiveness and success of such early-intervention programs have been well documented (Zigler & Berman, 1983).

There are few more obvious social facts than the overwhelming discrimination to which black people have been exposed throughout American   history. The clear environmental differences between black people and white people seem, to most social scientists obviously related to the difference in average IQ. The fact is, however, that black people and white people do inherit somewhat different genes, which affect, among other things, skin color and hair texture. Thus it is difficult to disprove the idea that genetic differences between the races might be responsible for the IQ difference. (Why one would want to prove or disprove such an idea is another question).

There seems little point in attempting to summarize in detail the multitude of research studies on black-white IQ differences. The topic seems almost to have obsessed some American researchers which in view of the importance of race in American society, seems scarcely surprising. There are studies to show that light-skinned black people have higher IQs than dark-skinned black people. This has been interpreted as indicating that degree of black ancestry is a predictor (genetically) of IQ. The same result, however, has also been interpreted as a consequence of the lesser discrimination against light-skinned black people. The fact that northern blacks have higher IQs than southern blacks (and than southern whites in some states) has been interpreted as a result of better educational opportunitybut it has also been interpreted as a consequence of selective migration of genetically bright black people from the South to the North or as a result of greater black-white intermarriage in the North. The point should be obvious: Until and unless black people have the same environmental experiences   as white people, those who wish to argue about the basis of the observed IQ difference will be free to do so. Their arguments may be ingenious, but they will be without convincing evidence.