Professor Emeritus Samuel Bowles, whose continued close ties with the department include teaching his graduate course on competition, coordination, cooperation and conflict, has recently published an important article in the journal Science. “Did Warfare Among Ancestral Hunter-Gatherers Affect the Evolution of Human Social Behaviors?” asks whether between-group conflict between tribes of early humans may have rewarded substantial within-group cooperation.
Much of the coverage included a riff on “War, What’s It Good For?” Here’s a more serious excerpt from the Wired report,
According to his analysis of archaeological evidence from Stone Age sites and and ethnographic studies of remaining tribes, combat between groups accounted for about 14 percent of all deaths in hunter-gatherer societies. Composed of a few dozen people with no social institutions, such groups were the dominant community form for most of human history.
“These were not modern societies. As with chimpanzees going out on patrol, there was no leadership. You could stay home if you wanted,” said Bowles.
After estimating the rate that altruism would reduce an individual’s chances of reproducing, Bowles plugged the numbers into a model of intergroup competition where an individual’s altruism would also improve a group’s chances of combat triumph. Groups with selfless individuals eventually predominated, and altruism predominated within those groups.
In addition to Emeritus status at UMass, Sam Bowles is Professor at the Santa Fe Institute and the University of Siena.