This chapter suggests that within relatively stable group- based hierarchies, most of the activities of subordinates can be characterized as cooperative rather than subversive to the system of group-based domination. It argues that it is subordinates' high level of both passive and active cooperation with their own oppression that provides systems of group-based social hierarchy with their remarkable degrees of resiliency, robustness, and stability. The chapter also suggests that this point is established at the fulcrum between: hierarchy-enhancing forces and hierarchy-attenuating forces. While social dominance theory has been influenced by models within personality psychology, social psychology, and political sociology, it is neither strictly a psychological nor sociological theory, but rather an attempt to connect the worlds of individual personality and attitudes with the domains of institutional behavior and social structure. Thus, social dominance theory is an attempt to integrate several levels of analysis into one coherent theoretical framework.