Categorization based on sex is the most basic social divide. It is the organizational basis of most major institutions, including the division of labor in the home, the workforce, politics, and religion. Globally, women's gendered roles are regarded as subordinate to men's. The gender divide enforces women's roles in reproduction and support activities and limits their autonomy, it limits their participation in decision making and highly-rewarded roles, and it puts women at risk. Social, cultural, and psychological mechanisms support the process. Differentiation varies with the stability of groups and the success of social movements. Gender analyses tend to be ghettoized; so it is recommended that all sociologists consider gender issues in their studies to better understand the major institutions and social relationships in society. (Contains 48 footnotes.)