Sexual segregation in childhood: a review of evidence for two hypotheses

In this paper, I review the evidence associated with two hypotheses, both ultimately derived from sexual selection theory, put forth to explain social sexual segregation in human juveniles. More proximately, I posit that segregation is motivated by sex differences in body size, physical activity and competitiveness. The first hypothesis, the energetic/behavioural hypothesis, suggests that difference in energetics is a way in which males differentiate themselves from females and develop muscle and brain systems implicated in reproductive roles. The second hypothesis, the social roles hypothesis, suggests that segregation is related to learning male and female reproductive roles. The reviewed evidence supports the view that there are differences in energetics in male and female groups. With development, the vigorous behaviours shown by males take the form of specific social roles, related to dominance and competitiveness for males and maternal roles for females.