Did Warfare Among Ancestral Hunter-Gatherers Affect the Evolution of Human Social Behaviors?, Science, 2009, 324, 1293-1298,
Since Darwin, intergroup hostilities have figured prominently in explanations of the evolution of human social behavior. Yet whether ancestral humans were largely "peaceful" or "warlike" remains controversial. I ask a more precise question: If more cooperative groups were more likely to prevail in conflicts with other groups, was the level of intergroup violence sufficient to influence the evolution of human social behavior? Using a model of the evolutionary impact of between-group competition and a new data set that combines archaeological evidence on causes of death during the Late Pleistocene and early Holocene with ethnographic and historical reports on hunter-gatherer populations, I find that the estimated level of mortality in intergroup conflicts would have had substantial effects, allowing the proliferation of group-beneficial behaviors that were quite costly to the individual altruist.
In the light of Jared Diamond getting sued for writing about social strife in New Guinea by the very people who have told him the stories of the violence in the first place it is very risky direction of research. According to "politically correct" explanations wars are charactersictic only for white, aggressive and doministic western civilization. Savages are, by definition, noble. Fortunately for Bowles his work is based on field research done by others, so the chances of beinf sued for putting some tribe "in bad light" are slim. But who knows...
Seriously - what I have found important was a careful combination of theory/model and observations. As it should be in science.