Differences between males and females have been documented for a number of behaviors. Among the environmental determinants of the development of behavioral sex differences is differential treatment of girls and boys by their parents and teachers. This paper reviews and comments on the research literature concerning differential socialization of the sexes. Areas covered include vocalization, social and affectional interactions, motor stimulation, dependency, aggression, sex-typed interests and activities, discipline, and achievement. It is noted that more information on differential treatment of girls and boys is needed for older children, for fathers, and for lower-class families. (Author)