Cautionary note

Imagine a society characterised by the following: An extended family works together to collect and store a staple plant food upon which all depend collectively. Division of labour means that while some family members maintain the granary, others forage for animal prey which are brought back to a central place for sharing. All combine efforts to rear the family's offspring communally, with some members even deferring their reproduction in order to care for younger kin. If a parent dies, an outsider is recruited as a replacement mate, rather than incest being committed. Family life is a complex balance of cooperation and competition over many years.

|This society is not imaginary but real. Moreover it is not a human, or even a primate, society but that of the acorn woodpecker (Stacey & Koenig, 1984). The plant food is acorns, and the animal prey is insects. These remarkable birds are mentioned here at the outset as a cautionary reminder that humans did not invent familial division of labour, nor are we necessarily its most impressive practitioners.

Why compare chimpanzees and hunter-gatherers?

Palaeo-anthropologists seeking to understand the evolutionary origins of human behaviour face a formidable obstacle. All of the players are long since dead and so are no longer behaving. Their stones and bones remain, and so provide a rich source of inference, but palaeo-psychologists must look elsewhere for acts and thoughts. The two main sources of data and ideas for these are modern foraging peoples and great apes. These supply the closest living approximations for calibrating the past process of hominisation.