People might have started cooperating in large numbers with unrelated individuals long before organizational structures emerged in ancient human societies, according to a PNAS paper by Sarah Mathew and SFI External Professor Robert Boyd, both of UCLA.
The two interviewed 118 men from the nomadic Turkana ethnic group of east Africa. The Turkana men regularly form impromptu raiding parties of several hundred men to seize livestock from other ethnic groups.
Some men are reluctant to participate in the raids because of the risk of being killed. Men who desert or behave in a cowardly fashion in battle, if judged so by their peers, can be tied to a tree and beaten. Mathew and Boyd speculate that this punishment helps drive cooperation in the absence of centralized government, and that this might have been the case in other pre-government human societies.
SFI Professor Sam Bowles agrees that punishment may have spurred the development of large-scale cooperation in human societies. He says such early cooperation may have set modern humans on the path to success.
Read the New Scientist article (June 13, 2011)
Read the PNAS paper (June 13, 2011)