A groundbreaking ten-year study on the behavior of chimpanzees, reported in the journal Current Biology, reveals that humanity's closest living relative expresses a propensity for human-like warfare. The nature of chimpanzee war, in which tribes patrol their own territory and violently annex the territory of other tribes in search of land and resources, is startlingly similar to the warfare that has consistently emerged throughout human history.

  • More Violent Than Humans Time's Michael Lemonick writes, "What's especially chilling about the observation is that the murder rate appears so high. The anthropologists couldn't be certain of how big a band the victims belonged to, because, unlike the aggressors, they weren't used to a human presence and thus couldn't be accurately counted. But even a conservative estimate suggests that the death rate is significantly higher than you would see in war between human hunter-gatherer groups."
  • Brilliant and Land-Hungry Discover's Ed Yong writes, "Chimpanzees are highly intelligent animals, capable of great acts of empathy, technological sophistication, culture and cooperation. But they can also be murderers. Groups of chimps, mostly male, will mount lengthy aggressive campaigns against individuals from other groups, attacking them en masse and beating them to death. Their reasons for such killings have long been a source of debate among zoologists, but the aftermath of the Ngogo murders reveals an important clue. After the chimps picked off their neighbours, they eventually took over their territory. It seems that chimps kill for land."
  • Demonstrates Strong Cooperation PhysOrg science blog says chief researcher John Mitani "cautions against drawing any connections to human warfare and suggests instead that the findings could speak to the origins of teamwork. 'Warfare in the human sense occurs for lots of different reasons,' Mitani said. 'I'm just not convinced we're talking about the same thing. What we've done at the end of our paper is to turn the issue on its head by suggesting our results might provide some insight into why we as a species are so unusually cooperative. The lethal intergroup aggression that we have witnessed is cooperative in nature, insofar as it involves coalitions of males attacking others. In the process, our chimpanzees have acquired more land and resources that are then redistributed to others in the group.'"
  • Chimps' Contradictory Nature Primatologist Nicholas Newton-Fisher recounts in the UK Independent, "Sitting amongst wild chimpanzees, watching two youngsters dangle from branches above their mothers' heads while the adults lie sleeping amid the buzzing of cicadas in the cool of the afternoon, it is easy to believe that these animals represent some lost Eden, a salvation from the human condition. To watch a full-grown adult male play-wrestle and chase an juvenile or adolescent, it is hard to imagine the callous brutality with which the same male can seize an infant from its mother's breast, tear into its abdomen with its canines and start feeding on the infant's intestines while it still lives. This is the contradiction in the behaviour of chimpanzees, one that brings them all too close to us."
  • 'Dark and Light' Also Present in Humans A staff editorial in the UK Independent muses, "Juxtapose the ability of chimps to care tenderly for their own kind with their evident capability ruthlessly to pull an alien infant from its mother's breast and tear it to shreds and you might be tempted to see a reflection of the dark and light sides of the human psyche. The complexity of the chimp, and the base primitivism of which homo sapiens is all too capable, might suggest that the gap between the species is smaller than was for centuries supposed."
  • Humans Also Close to More Peaceful Bonobos Primatologist and bonobo expert Vanessa Woods writes, "We have to find a way to be more like bonobos. They share 98.7% of our DNA. ... No bonobo has ever been seen to kill another bonobo. There is very little violence towards females. The infants get an idyllic childhood where they do nothing but hang out with their moms and get anything they want. There is plenty of food. Lots of sex."