Sexual Selection and Sex Differences in
David C. Geary
For the most part, the psychological study of cognitive sex differences has been an empirically driven endeavor, that is, sex differences were found on certain cognitive measures and the field has coalesced around these findings. Traditionally, the associated studies and theoretical models have focused on the advantage of men in the general domains of spatial and mathematical cognition and the advantage of women in verbal cognition (e.g., chapter 6; Halpern, 1992). The search for the origin of these sex differences has sometimes focused on biological factors, particularly sex hormones (chapter 3) (Kimura, 1999). Most theories, however, have focused on presumed culturally mediated (e.g., parental socialization) differences in the activities and experiences of boys and girls and later of men and women (chapter 7) (Benninger & Newcombe, 1995; Eagly, 1987). The goal here is to provide a unifying framework based on the principles of sexual selection for incorporating hormonal, experiential, as well as evolutionary influences on human cognitive sex differences.
Sexual selection is an advantaged theoretical perspective for studying cognitive and other sex differences, for many reasons. The ultimate (evolutionary) and proximate (here and now, such as sex hormones) mechanisms associated with sexual selection have been studied in hundreds of species and are well understood (Andersson, 1994; Darwin, 1871). Basically, sexual selection provides a theoretical framework for understanding human cognitive sex differences in the context of sex differences found in other species and, at the same time, allows for hormonal, developmental, and experiential influences on the expression of these differences. Sex differences in social cognition will be discussed to illustrate the util