Camp stability predicts patterns of hunter-gatherer cooperation

Food-sharing is more prevalent in stable hunter-gatherer camps, shows new UCL research that sheds light on the evolutionary roots of human cooperation. The research explores patterns of food-sharing among the Agta, a population of Filipino hunter-gatherers. It finds that reciprocal food-sharing is more prevalent in stable camps (with fewer changes in membership over time); while in less stable camps individuals acquire resources by taking from others - known as 'demand sharing'. Exploring social dynamics in the last remaining groups of present day hunter-gatherers is essential for understanding the factors that shaped the evolution of our widespread cooperation, especially with non-kin. The study, published today in the Royal Society journal Open Science, is the first to report a real-world association between cooperation and group stability. First author of the study, Daniel Smith (UCL Anthropology), said: 'Cooperation between unrelated individuals is rare in animals, yet extensive among humans. Reciprocity - the principle of 'you scratch my back, I scratch yours' - may explain this non-kin cooperation, yet requires stable groups and repeated interactions to evolve. 'Our research shows that hunter-gatherer cooperation is extremely flexible - reflecting either reciprocity or demand sharing depending on the frequency of repeated interactions between camp members.' The authors looked at patterns of actual food-sharing from six camps to examine whether associations between patterns of food-sharing and camp stability were present, asking each household at the end of each day, 'Which households did you receive food from today??