The Heritability Hang-Up

Abstract

The nature-nurture issue has provided some of the most keenly contested debates in the fields of biology, psychology, sociology, and physics during the past 5 years. As is well known, the same questions have been a source of controversy for more than a hundred years in diverse political and social climates. From time to time, practical measures have been implemented whose nature has often depended on the relation between the political ideals of the regime of the time and the ideals of the contemporary scientific participants in the naturenurture controversy. Some of the history of this interaction in the United States as it pertains to intelligence has been surveyed by Kamin (I) and Allen (2). The most recent explosion of interest in the question is probably attributable to Jensen's (3, 4) contention that, since inequalities in cognitive performance are largely genetic in origin, environmental intervention through educational or social innovations will be of minimal value in reducing these inequalities. The premise for this argument is based on Jensen's analyses of the data from a large number of empirical studies. From these analyses, Jensen also argues that there is probably a strong genetic component to the observed differences in mean IQ between black and white children in the United States. The analyses and arguments that were made by Jensen for IQ, and by others for