Regulating norm violations is key for the evolution and maintenance of large-scale human cooperation. Across societies, people are sometimes willing to punish norm breakers via direct confrontational tactics or via indirect means such as gossip and ostracism. At the same time, there is substantial cross-societal variation in the mechanisms, norms, and institutions that promote cooperation. In this talk, I will present two interrelated lines of research on the psychological and cultural foundations of norm enforcement. In the first research line, I investigate the proximate—cognitive and emotional—mechanisms underlying direct and indirect responses to norm violations, using experimental and experience sampling methods. In the second research line, I examine cross-societal variation in the role of guilt and internalized norms versus shame and external social pressures in promoting prosociality, using a decision-making experiment in 20 industrialized countries. Together, these studies address longstanding questions regarding the prevalence of punishment in field settings, the psychological mechanisms supporting prosocial and punishment behaviors, as well as cultural universals and differences in norm enforcement systems. To close, I discuss how my future research program will build and leverage secondary datasets on norm enforcement across non-industrialized and industrialized societies, and use novel experiments to study the cultural evolution of punishment institutions.