S. E. Cross and L. Madson (1997) proposed that women and men differ in self-construals, with women as interdependent and men as independent, and that these construals are seen to underlie many sex differences in social behavior. In this article, the authors address the issues of sex differences in self-construals, the stability of self-construals, and the centrality of interdependence-independence to sex differences. They examine the proposal next from a developmental perspective, suggesting that development of the self does not precede children's gender-related behavior. Evidence regarding the socialization processes that may contribute to sex differences in self-construals is largely inconclusive, especially regarding the differential treatment of boys and girls by parents. Their developmental perspective provides insights into ways that Cross and Madson's approach can be elaborated to explain sex differences in social behavior.