Dominic Johnson

I recently returned from a workshop on “Evolutionary Perspectives on War” at the University of Oregon at Eugene. This was perhaps the first ever meeting to exclusively examine the links between evolution and war. In attendance were researchers from a number of disciplines including archeology, anthropology, primatology, evolutionary psychology, and political science (including, for example, Sam Bowles, Napoleon Chagnon, Steve LeBlanc, Pat Lambert, Rose McDermott, John Orbell, Randy Thornhill, John Tooby, Phil Walker, Frances White, and Richard Wrangham).

The general message of the workshop was clear. There is a plethora of evidence that warfare stretches as far back into human history and prehistory as we can see, and every reason to suspect that warfare exerted a significant selective pressure on the evolution of human psychology and behavior. Humans, particularly men, display a number of adaptations for forming coalitions, aggression, and warfare. Highlights included the ecology of lethal inter-group violence among chimpanzees (Wrangham), the prevalence of warfare as a cause of death in archeological and ethnographic records (Lambert, LeBlanc, Walker), and the role of personality, inter-group threat, and disease in human conflict (McDermott, Thornhill, van Vugt).

My own presentation explored the implications of Lanchester’s Laws of Combat for human evolution. The basic idea is that, where combat is fought as an all-against-all melee, combat power is proportional not to group size but to group size squared (i.e., a force three times larger than its enemy is actually nine times more powerful in combat). This offers a complementary explanation for why coalitions were so important in human evolutionary history, and why groups of men may be particularly prone to aggression-the costs of violence against smaller groups can be very low.

Links:

Eugene’s Institute of Cognitive and Decision Sciences

Write-up in New Scientist