Social and cultural behaviour in non-human primates : investigating coordination, cooperation, and cultural transmission

Social and cultural behaviours in non-human primates provide essential insights into their diverse lives and into the evolutionary origins of human behaviour and society. This thesis employs a comparative, interdisciplinary approach to investigate how primates coordinate, cooperate, and transmit cultural behaviours. I engage with the central debates surrounding cooperative and cultural behaviour by integrating broad perspectives that aim to understand the conditions under which such behaviours emerge, persist, diversify and evolve. In the first chapter, I develop a framework joining ideas from both cultural attraction and social learning theories that emphasizes how individual predispositions, social contexts, and ecological conditions dynamically shape behavioural rigidity and flexibility. Chapter two builds from this framework to experimentally investigate how coordinated behaviour might stabilize learned behaviours in chimpanzees. Broadening to cooperative behaviour, chapter three explores reciprocal helping behaviour in gorillas, demonstrating how reward structure influences cooperative strategies and how the capacity for reciprocity may not rely on complex calculations. Finally, in chapter four I use a zone of latent solutions inspired approach with a group of Japanese macaques, challenging the role of social learning in the expression of stone handling traditions and investigating how ecological and motivational affordances may align to support the emergence and diffusion of the behaviour. Collectively, the research presented in this thesis argue against the reliance on cognitively complex mechanisms to explain the capacity for diverse cultural and cooperative behaviours. Instead, these findings contribute to ongoing debates by showing how distributed and context-sensitive processes can underly the rich social behaviours of primates, and from which our own behaviours may have evolved.