Gender differences are a provocative subject with good reason: they are implicated as contributors to important societal problems. Gender differences in math achievement contribute to limited career options for women (Center for Early Adolescence, 1984; Stipp, 1992), which may in turn affect their economic self-sufficiency. Gender differences in social norms about competition and closeness contribute to power and communication problems in female-male relationships, with consequences for family stability and domestic violence (Leaper, 1994). Understanding the origins of gender differences, therefore, has important societal implications.