Did warfare among ancestral hunter-gatherers affect the evolution of human social behaviors?

Science. 2009 Jun 5;324(5932):1293-8. doi: 10.1126/science.1168112.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Altruism*
  • Anthropology, Cultural
  • Archaeology
  • Biological Evolution*
  • Cooperative Behavior
  • Cultural Evolution*
  • Female
  • Genetic Variation
  • Humans
  • Male
  • Microsatellite Repeats
  • Models, Theoretical
  • Social Behavior*
  • Warfare*