Food culture as a mechanism of social bonding and social identity in primates.

Food culture is one of the identifying features of social life of any human being every day. The shared habits, rituals and beliefs around producing, procuring and consuming a wide variety of food types, textures and flavours shape how we feel and behave towards others. Food culture defines who we are, our identity and everyday values, and shapes social relationships. This helps us live in complex societies, where we form connections not only with family, but also with society at large and even far-away countries. However, food-related behaviours rarely leave traces in the fossil record, making the evolutionary origins of food culture difficult to reconstruct. Studies of non-human primates help clarify its evolution in the human lineage. Yet research on primate culture has focused largely on social learning and tool use, with relatively little attention given to the cultural dimensions of feeding behaviour. Here we propose that food culture may function as a mechanism of social bonding and social identity in primates, as it does in human groups. Drawing on the Social Brain Hypothesis, we suggest that shared dietary traditions-socially transmitted food preferences-may maintain cohesion in socially complex systems characterised by large groups, fission-fusion dynamics, and tolerant intergroup encounters. Behavioural similarity arising from shared food preferences may facilitate social bonding in complex social systems, providing an additional mechanism when tracking individual relationships becomes cognitively demanding. In humans, cultural behaviours such as food preferences are used to identify others as having the same identity or a different identity. This sense of social identity then affects how we treat others, with members displaying same cultural characteristics favoured over members where these characteristics are absent. This paper proposes that food culture may play a comparable role in primate social systems. We develop a conceptual framework to examine whether dietary traditions are present among primates, contribute to social complexity, influence tactical ranging decisions, and extend beyond feeding preferences to include traditions in vocalisations during feeding. This framework provides testable predictions for understanding how food culture may act as a socio-cognitive mechanism underpinning social bonding and the evolution of human food practices.