Gender differences in inhibitory control as assessed on simple delay tasks in early childhood: A meta-analysis

Bjorklund and Kipp (1996) hypothesized that due to selection processes operative during human evolution, females have an inborn advantage over males in the ability to suppress inappropriate responses on tasks in the behavioral and social domains. To test this hypothesis, a meta-analysis was conducted on gender differences on simple delay tasks in which the participant is required to wait for a “go” signal before making an approach response to an enticing stimulus. The meta-analysis was performed on 113 effect sizes derived from 102 studies of 21,378 children who ranged in age from 1 year to 9 years and who lived in at least 15 countries. As hypothesized, girls exceeded boys in delay ability, with the gender differences being small in magnitude (Hedges’ g = .25–.26). The female advantage in delay ability held for both U.S. and non-U.S. samples of children. Further analyses found that girls outperformed boys on each of four simple delay tasks. Although the magnitude of the gender difference on the individual simple delay tasks did not differ as a function of age, the age ranges covered were narrow. Discussion focuses on two issues: (a) whether gender differences in delay ability can be explained by a factor other than inhibitory control and (b) whether parental socialization processes can explain the gender differences in delay ability. The evidence reviewed does not provide substantial support for either of these possibilities.