Results of research investigations on sex differences suggest that: (1) those few differences which exist are average group differences; (2) biological and sociocultural factors are possible influences on observed sex differences; and (3) research on sex differences is basically inconclusive. Research examining these differences is inextricably intertwined with social policy, suggesting that the "whys" of sex differences are related to the "whys" of sexually differential status in American society. (Author/HLM)