A new study finds that violence in chimps occurs naturally, not as a byproduct of human intrusion. It’s also more common than might have been believed. The study says that violence in chimps comes from natural, evolved tendencies towards physical aggression and sometimes results in “chimp wars” where members of chimpanzee communities attack other groups en masse.
The study was published in Nature and sheds light on the evolutionary roots of lethal conflicts among primates. Chimpanzees, our closest known relative, show behavior similar to humans in this regard. Violence in chimps happens regularly.
“Most killings involve gang attacks,” Michael Wilson, who led the new study, told Discovery News. “When attacking adults, many attackers pile onto the victim. They pin the victim to the ground and hit, kick and bite the victim.”
The researchers analyzed 426 combined years of research to include 18 chimpanzee study sites and four bonobo sites. Group killings were documented at 15 of the 18 study sites but only once at bonobo sites. This showed the tendency towards violence in chimps versus other primates.
“Males kill more often than females in both species, and humans and chimpanzees share an unusual pattern of cooperating to kill.”
David Morgan, quoted above, is a research fellow with the Fisher Center for the Study and Conservation of Apes at Lincoln Park Zoo in Chicago and one of the participants in the study. He has been studying champanzees in the Republic of Congo for fourteen years and was interviewed in the Chicago Tribune regarding this study on violence in chimps.
The study has its detractors, of course, who argue that the violence in chimps model still supports the human intervention cause for lethal violence. They say, according to the New York Times, that the measures of human impact on chimpanzees in the study are inadequate. Study lead Wilson, however, counters with the point that the Ngogo group of chimpanzees in the Uganda was the most violent group of chimps known, and it is also the least human-impacted of the study. Morgan agrees, citing his own study group in the Congo, also featuring low human impact.
The issue of violence in chimps is one that can hit close to home for humans. Last year, a headline story in New Scientist detailed the violent death of Pimu, a leader of a cohort of chimpanzees who was attacked and killed by his own tribe. The story showcased how similar violence in chimps and humans can be.
“We’re trying to make inferences about human evolution,” said Wilson to the New York Times. This, for many, likely sums up the latest findings about violence in chimps.