Sex difference in sports interest: What does evolution say?

First, the authors demonstrated that females' underrepresentation in sport--both as participants and spectators--generally reflects their lesser sports interest, not merely fewer opportunities for involvement. Moreover, this sex difference occurs in all societies described thus far, from hunters and gatherers to large contemporary societies. For example, in every society with available data, males participate in sports at least twice as much as females in terms of frequency or duration.

Next, the authors explored adaptive, functional hypotheses for sports. These are accounts of why humans would have evolved dispositions to be interested in sports, particularly how such dispositions could have affected the likelihood of survival and reproduction. Two hypotheses seem relevant for both males and females. One hypothesis focuses on the importance of needing to ally with coalitions in between-group contexts, while the other emphasizes the need to develop social and motor skills. Another hypothesis holds that individuals compete in sports to gain status and that nonparticipants monitor sports performances so they can evaluate potential competitors and allies. The evidence indicates that this hypothesis applies chiefly to males. A fourth hypothesis is that sports serve as courtship displays that advertise participant quality to the opposite sex. This hypothesis effectively explains some aspects of females' sports interest.

Finally, the authors examined the proximate or near-term causes for the sex difference in sports interest. Although it is often assumed that socialization practices entirely cause this sex difference, the evidence that socialization plays a role remains equivocal. In particular, no experimental manipulation or systematic historical comparison has ever shown a decrease in the sex difference. Moreover, several studies indicate that prenatal hormones contribute to males' greater sports interest.

The take-home points from this review are that the sex difference in sports interest is (1) substantial and widespread, (2) partly due to evolutionary pressures that differentially affected males and females, and (3) unlikely to be fully overturned by socialization. These points challenge the bedrock assumptions of many scholars and policy makers. Most notably, Title IX is a U.S. law that prohibits sexual discrimination in educational opportunities, including sports, and Title IX is generally implemented under the assumption that females' sports interest is intrinsically equal to that of males. The present research indicates that this implementation may require revision.