It is anthropologist Napoleon Chagnon that controversially argued back in 1988 that the supposed extreme violence among the Yanomamo people of Amazonia was an evolutionary trait, and evidence of a primordial human nature that is predisposed to violence. In Chagnon’s study, men who had killed had more wives and offspring than men who had not killed.
But do humans really have an evolved tendency to form coalitions to kill out-group political communities? And does chronic raiding and feuding characterize life in a state of nature?
Writing in Science, Fry and Soderberg answer in the negative:
The findings suggest that MFBS [mobile forager band societies] are not particularly warlike if the actual circumstances of lethal aggression are examined. Fifty-five percent of the lethal events involved a sole perpetrator killing only one individual (64% if the atypical Tiwi are removed). One-person-killing-one-person reflects homicide or manslaughter, not coalitional killings or war. Additionally, 36% of all lethal events occurred within the same local group (62% if the atypical Tiwi are removed), and violence within a local group is not coalitional war. Only 15% of the lethal events occurred across societal lines. Some such events might fall within a definition of war, whereas others might not (such as when shipwreck survivors were killed). Finally, very few lethal disputes were over resources. Overall, a consideration of reasons for lethal aggression reveals that most cases stemmed from personal motives consistent with homicide and, in some cases, family feuds, but much less often with lethal aggression between political communities, or warfare.
Notice that this finding does not rule out a Hobbesian war of all against all in the state of nature. It just means that inter-communal warfare is not an inherently human thing.
H/T The Economist