Renowned for his meticulous fieldwork, especially with chimps in Uganda’s Kibale National Park, Wrangham showed just how common chimp brutality is. Goodall had acknowledged with frank regret that her beloved chimpanzees could be quite violent. One mother and daughter killed the infants of other females in their group. Males often coerced and beat females, and would sometimes gang up and attack a chimp from another group.
At Kibale, large groups of chimps range together, and aggression escalates accordingly. Wrangham observed as these bigger parties of males got excited and went out on “patrol” in what looked like an organized way: They walked along their territorial border, attacking lone chimps from neighboring communities when they came across them en route. In his 1996 book, Demonic Males, co-authored with Dale Peterson, Wrangham recapped this and other evidence to draw a dire portrait of humanity (the male version) as inherently violent by evolutionary legacy. Here was vivid support for a Hobbesian view of human nature, rooted in genetics.
Not fully Hobbesian, perhaps, but fascinating nonetheless.