Cognitive sex differences and mathematics and science achievement.

Abstract

Spelke (December 2005, p. 950) considered “three claims that cognitive sex differences account for the differential representation of men and women in high-level careers in mathematics and science.” The focus of this comment is on the claim regarding gender differences in mean levels of cognitive abilities. Spelke claimed (p. 954) that “most investigators of sex differences have concluded that males and females have equal cognitive ability, with somewhat different profiles.” There are two major components to this comment. The first is mainly theoretical, and the second is both theoretical and empirical. The first component has to do with the basis for asserting that males and females have “equal cognitive ability.” The problem with this assertion is that since the early 1900s, modern intelligence researchers and theorists have documented extensively mean sex differences on many, if not most, cognitive ability measures. For some abilities, the differences between the sex groups is small (e.g., as in the case of abstract reasoning—see Lynn & Irwing, 2005), but for other abilities the differences are quite large (e.g., mechanical reasoning; see Halpern, 2000). As a result, whether males or females have higher mean general intelligence depends on the operationalization of the content of the tests selected to assess cognitive ability. Early test developers realized this problem but dealt with it in two strikingly different fashions. Yerkes, Bridges, and Hardwick (1915) concluded that these differences required separate norms for males and females: