Cracked Bell

James J. Heckman from the March 1995 issue

(Page 4 of 4)

The authors' argument in support of local neighborhoods and small communities with cognitively mixed populations cries out for clarification. For each idyllic fable about the virtues of life in small communities, one could counter with fables of Peyton Place or the narrow-mindedness of the Babbitts of Main Street.

Had the authors been more cautious, they would have told the following defensible story: They have produced very convincing evidence that by the late teenage years, essential features of the skills and motivation of persons are determined. These features strongly influence individuals' performance in schools, in the market, and in other aspects of social life. The Armed Forces Qualifying Test seems to be a good measure of the skills affecting social performance. Using the components on which the test is based, rather than one composite score, would probably capture the diversity of abilities in the population even better.

The authors have no good way to separate genetic from social influences on social behavior. Their environmental data are too crude and the AFQT score they use is obtained too late in life to make a genetic-environmental distinction meaningful. The authors would require much finer measures of environmental variables than they have at their disposal to rule out the importance of family and society in determining individual outcomes.

Nonetheless, their evidence and the evidence assembled from many government skill-remediation programs for adults suggests that persons are not very malleable after their late teens or perhaps their early 20s. Successful interventions for such people are likely to be very costly. The literature suggests a particularly poor performance of educational remediation programs for adults of low cognitive ability as measured by AFQT and other cognitive tests.

To the extent that social interventions can upgrade skills, they are most likely to be effective when they are applied to the young. The fragments of evidence summarized in Chapter 17 of the book, and other evidence from high-intensity enriched-environment programs, point in this direction. This evidence is also consistent with the work of Thomas Sowell, who stresses the role of culture and values in shaping the expectations and motivations of young children. Job training and education are generally wasted on low-IQ adults. For this group, subsidies for employment may be justified, especially if work improves social behavior or is valued for its own sake. Economic efficiency is promoted by investing in the young. There is much evidence that learning is a cumulative, dynamic process. Learning begets learning. It is much easier to galvanize a young child than an illiterate young adult.

Future research should focus on growth and development in measured ability prior to age 15 (the age of the youngest person in the Murray-Herrnstein sample), because existing research indicates that values are formed and cognition is developed prior to that age. Genes may play some role, but culture and environment also contribute to ability and motivation. Much serious research in psychology indicates that motivation and attitude are as important--and possibly more important--for success than is raw IQ.

As for social policy, we should recognize that heterogeneity in experiences and endowments produces a wide range of cognitive skills and motivations. For a variety of reasons, treating persons fairly as individuals may lead to heterogeneity in outcomes among demographic groups. Denying individual heterogeneity by treating persons as members of demographic categories will produce disparities in productivity among demographic groups, reduce economic efficiency, and foster a sense of injustice among all participants in society.