Race and IQ *

On standardized intelligence tests, black Americans score an average of 10-15 IQ points lower than white Americans. There is no debate on this point. The controversy revolves around the interpretation of this difference. Some experts believe that the two groups differ in inherited abilities. Others argue that the difference in average IQ can be caused entirely by environmental differences between the two groups. A third view holds that genetic and environmental differences are so entwined that we cannot adequately resolve the controversy now. Let's look at some of the main points in this controversy.

  1. Although blacks and whites might differ in physical appearance, they do not represent two distinct biological groups. From what we know about genetic structure, there are more differences within races than between them.
  2. Among blacks, there is a tendency for lightness of skin color a possible indicator of degree of intermixture with white genes to relate to higher IQs. However, these correlations are low about +.15. Rather than genes, this trend can be explained on the basis of environmental differences the lighter skin color is associated with less discrimination and greater opportunity.
  3. A study was done on the illegitimate children fathered by U.S. servicemen during the occupation of Germany after World War II. These children were all raised by German mothers of similar social status and were matched with children of the same age in their classrooms. The study found no overall difference in average IQ between children fathered by blacks and those who were fathered by whites. These results provided strong support for the environmental view of racial IQ differences.
  4. Some black or interracial children those with one black parent were adopted before the age of one. The children were raised by white families with above average incomes and educations. These children corresponded to the white average by scoring over 15 points above underprivileged black children raised by their biological families. Even on school achievement tests, the performance of these adopted children was slightly above the national norms.
  5. One environmental theory is that blacks in America are in a social position similar to other caste-like minorities in the world the Harijans (untouchables) of India, the Maoris of New Zealand and the Burakumi of Japan. The IQ differences between the deprived groups and the privileged groups in each country are about the same as the difference between blacks and whites in this country. The Burakumi are particularly interesting. In 1871, they were freed from their lowly status due to their despised work as tanners but they are still treated as outcasts in Japan. However, when the Burakumi immigrate to America, their children are treated as any other Japanese in the United States. Here the Burakumi children do as well on IQ tests and in school as other Japanese-Americans.
  6. Being born into a caste-like minority leads children to grow up with the conviction that life will hold limited opportunities. The lower IQ of these children becomes a self-fulfilling prophecy teachers expect less from them and tend to treat them in ways that make the teachers' expectations come true. The effect of these attitudes is shown in a 1986 psychological study of two groups of equally bright black students. One group was doing well, while the other was failing in school. Those who did poorly regarded being studious as betraying their racial identity. In their own words, doing well meant that they were "acting white." They saw doing well in school and getting high-status jobs as selling out to white values. Similar dynamics occur among Mexican-American children they identify school achievement as betraying their roots.

  7. Over the past few decades, various testing organizations have found a consistent reduction in the achievement gap between blacks and whites. These reductions occur for reading and math achievement tests from grades 1-12 and for the SAT (Scholastic Aptitude Test). The consistency of this trend suggests that differences will be further reduced in the future. The social changes affecting blacks have been enormous in the last 20 years. These changes are likely to raise the hopes of black youth and give them evidence that school achievement will improve their prospects for later success. This hypothesis of continued improvement is consistent with the changes in the last few decades.

From the available evidence, there is no way that we can conclude that there are innate racial differences in intelligence. Cultural and environmental differences between blacks and whites influence the development of intelligence in complex ways. Up to now, no study has been able to accurately estimate or eliminate these effects. As long as there are systematic differences in the ways that blacks and whites are raised and as long as the effects of these differences cannot be reliably measured it is impossible to make any valid conclusions about innate racial differences in intelligence.

* Adapted from Atkinson, Atkinson, Smith and Bem's Introduction to Psychology, Harcourt brace Jovanovich Publishers, 1990, pages 468-469.

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