From traditions to social cultures: rethinking the evolutionary origins of primate culture

Abstract The legacy of Frans de Waal reshaped our understanding of animal sociality, demonstrating that culture in nonhuman primates extends beyond learned acts to encompass the organization of social life itself. Building on this foundation, I conjecture that the primary evolutionary unit of culture is not the discrete social tradition — such as the grooming handclasp in chimpanzees or eye-poking in capuchins — but the social culture: the shared, enduring norms that regulate conflict, affiliation, and cooperation within groups. Evidence from de Waal’s work on macaques and Sapolsky’s long-term studies of baboons reveals that tolerant or despotic social styles can be socially learned, transmitted across generations, and maintained even after membership turnover. Such cultures may alter rates of aggression, reconciliation, stress physiology, and survival, thereby potentially exerting direct fitness effects. I outline several research priorities for uncovering the behavioural mechanisms of social cultural transmission — female-mediated social induction, developmental social inheritance, cultural tipping points, and individual variation in norm adoption. Reframing primate culture in this way shifts focus from the replication of behaviours to the inheritance of social systems, linking proximate processes of social learning with the ultimate selection pressures that favour social stability. This perspective, inspired by de Waal’s enduring insights, endeavours to situate social culture as the most evolutionarily consequential expression of culture in nonhuman primates and a key precursor to the moral and institutional cultures of humans.