In this paper, emphasis is placed on examining the issue of sex differences from a historical perspective, within a framework focused on socialization factors, and within a more psychological framework that examines how society's beliefs and expectations are reflected in personal beliefs that may affect functioning. Biographical details about several female mathematicians are discussed first. Then research on parental factors that influence children's performance are reviewed, followed by a summary of school and teacher factors. How peer group values affect mathematics participation and achievement are next discussed. Finally, psychological explanations derived from research are presented. (MNS)