British Academy: The UK's National Academy for the Humanities and Social Sciences
Social Brain, Distributed Mind
Abstract
Fission-fusion behaviour in Chimpanzees and Hunter-gatherers
Robert Layton (Durham) and Sean O'Hara (Liverpool)
Our primary data on hunter-gatherers are taken from ethnographic studies of 27 hunter-gatherer peoples, ranging from those who occupy the same environment as chimpanzees and those occupying similar environments on other continents, to those occupying very different environments such as tropical and arctic deserts. We shall reiterate some well-known aspects of hunter-gatherer society (e.g. meat sharing, home bases), but also put forward some novel arguments. The well-known phenomenon according to which the hunter giving away much or all of his catch needs to be explained within a lifetime's perspective, since women continue to forage successfully into old age, but men's contribution declines as their eyesight fails. We argue that the human community seems the best parallel with the chimpanzee community, and bands are better seen as intermediate groups that have crystallized during human social evolution, emerging as social bonds of co-operation and reciprocal exchange between individuals became stronger during the evolution of modern hunter-gatherer strategies. Human communities occupy much larger territories that chimpanzees, both because the communities are bigger, and because humans live at lower population densities, even when adjusted for body weight. This is probably related to the greater contribution meat makes to diet. Consequently, and unlike Chimpanzee communities, no-one will know all other members, and people often meet less frequently.