Success in competition between groups is more likely when competition and conflict within groups is moderated, says SFI Professor Sam Bowles in an essay describing how cooperative human institutions, aided by conflict, could have evolved in human society.
"For ancestral humans, making peace was no less essential than surviving wars," he writes.
His piece in today's issue of Science, part of a special issue themed "Why we fight," describes how civic norms and conventions -- such as voluntary tax compliance, willingness to risk danger in war for a ruler or nation, respect for property rights -- allowed for cooperative groups to prevail in conflicts with other groups.
Over many millennia, such a conflict-driven culling process may account for the buildup of increasingly complex forms of human cooperation -- cities, markets, democracy -- and the first emergence of nation states, not only in China, but also in Mesopotamia, Mesoamerica, Peru, Egypt, and the Indus Valley.
"National states won wars," he writes.
He also describes how within-group shifts from one accepted social convention to another almost always required the often risky collective action of many individuals who were at odds with those who were most invested in the status quo.
"It is no surprise that shifting from one convention to another generates conflict, whether violent or civil," he writes. "This is why strikes, demonstrations, and wars provide so many of the punctuation marks of history."
Citing evidence from genetics, archaeology, ethnography, and history, he points out, though, that competition and warfare were not only important results of shifting social norms, but also forces in human genetic and social evolution that were necessary for complex forms of social organization were to arise as they did.
"I have shown that we can plausibly infer from these data that the degree of mortal conflict and extent of genetic differences among ancestral forager groups were jointly sufficient to have allowed the evolution of a genetically transmitted predisposition to contribute to common projects," he writes.
"In addition to making war, our hunter-gatherer ancestors almost certainly built institutions to share food and information, to make decisions by consensus, and to gang up on would-be dominants or free riders who would monopolize reproductive and material resources or exploit the cooperation of others. These practices, called reproductive leveling, reduced within-group differences in material wealth and reproductive success, resulting in a less-tilted evolutionary playing field and giving the altruistically inclined a better chance of survival."
"Whatever the balance of cultural and genetic factors in the evolution of human cooperativeness, between-group conflict almost certainly played a pivotal role."
He adds, however, that future human social and cultural advances may yet hold promise for human cooperation without the more violent aspects of conflict.
Read the article in Science (May 17, 2012)
More about Bowles's research