Whether and how societal structures shape individual psychology is a foundational question of the social sciences. Combining insights from evolutionary biology, economy, and the political and psychological sciences, we identify a central psychological process that functions to sustain group-based hierarchies in human societies. In study 1, we demonstrate that macrolevel structural inequality, impaired population outcomes, socio-political instability, and the risk of violence are reflected in the endorsement of group hegemony at the aggregate population level across 27 countries (n = 41,824): The greater the national inequality, the greater is the endorsement of between-group hierarchy within the population. Using multilevel analyses in study 2, we demonstrate that these psychological group-dominance motives mediate the effects of macrolevel functioning on individual-level attitudes and behaviors. Specifically, across 30 US states (n = 4,613), macrolevel inequality and violence were associated with greater individual-level support of group hegemony. Crucially, this individual-level support, rather than cultural-societal norms, was in turn uniquely associated with greater racism, sexism, welfare opposition, and even willingness to enforce group hegemony violently by participating in ethnic persecution of subordinate out-groups. These findings suggest that societal inequality is reflected in people’s minds as dominance motives that underpin ideologies and actions that ultimately sustain group-based hierarchy.