AbstractIn recent years there has been a trend in the social sciences in general, and in psychology in particular, to revive biological determinist theories of human behavior. This trend has been most evident in relation to race and sex differences. Because of their controversial nature, these views have not remained confined within the scientific community, but have gained fairly wide circulation in the popular media. Their contribution to the debate on racial and sexual discrimination has not always been limited to justifying current discriminatory practices; some authors have gone so far as to recommend new forms of discrimination. The purpose of this paper is to examine some of the kinds of data on which biological determinist views of sex differences have been based and to see whether the data justify the interpretations.