Male chimps and humans are genetically violent---NOT!

Is violence in our genes?

Posted Mar 29, 2011

Do chimpanzees in the wild want to kill others? Is murder common among wild chimpanzees? Do male chimps (and their cousin male humans) have "killer" "demonic" instincts towards their fellows? If you look at the data, the answer to these questions is a resounding NO! But these beliefs are "gospel" in much of popular science. This misinformation colors our view of humans and human nature. What are the ramifications?

Sociobiological or evolutionary psychology theory, popular among most science writers, can mislead, telling us "just so" stories that fit current cultural norms and treating them as facts (Hart & Sussman, 2009).

Donna Hart and Robert W. Sussman (2009) go through the paltry data that is used to support chimpanzees as "demonic males" (Wrangham & Peterson, 1996). I cite their arguments here.

Let's start with the evidence that chimpanzee males are murderers. This view is a recent one. Early research on chimpanzees found them to be unaggressive and peaceful. For decades, Jane Goodall studied chimpanzees at the Gombe National Park in Tanzania. During the first 14 years of study, aggression patterns were no different from other primates (peaceful and unaggressive). In one year of detailed study, for example, about 28 encounters were classified as violent, most with no discernable injury, such as brief hitting followed by an embrace.

Patterns of aggression changed in the Gombe chimpanzee troop after 14 years. With hindsight, it turned out that human feeding of the chimpanzees, with its restrictions and control, deeply affected the behavior and culture of the chimpanzees, such as keeping large groups of animals near the feeding site which promoted increased fighting among the males. Margaret Power in The Egalitarians, Humans and Chimpanzees: An Anthropological View of Social Organization, examines how human interference created the unusual aggressive behavior of the chimps.

Ignoring Power's work, Wrangham and Peterson contend that similar violent behavior was found among chimpanzees across Africa. But Hart and Sussman dismantle their five exhibits of "evidence."

(1) Goodall reports a so-called raiding party in 1982 in which a female was chased and mildly attacked and her 4-year-old son was sniffed.

(2) A 35 year old male's body was found in 1981. With no evidence, murder was inferred. Males rarely live past 33.

(3) "From 1970 to 1982 six adult males from one community disappeared at a Japanese study site in the Mahale Mountains of Tanzania, west of Gombe," one by one over a 12 year period. With no evidence, murder was inferred. But lions are common predators of chimpanzees in that region.

(4) Wrangham and Peterson misreport statements by Christopher and Hedwige Boesch, saying that they said "violent aggression among the chimpanzees is as important as it is in Gombe" whereas they really said, according to Hart and Sussman is that "encounters by neighboring chimpanzee communities are more common in their site than in Gombe and that this may lead to larger, more cohesive, group structure and a ‘higher involvement of the males in social life'-there is no mention of any violence or killing during these encounters" (p. 210).

(5) At the site Wrangham had studied since 1984, a male's body was found in 1991 a few days after the troop's males had been exchanging calls with another community. The researchers had not seen any violence, nor was there any in the 7 years prior or 6 years after the incident. With no evidence, murder was inferred.

Did you know the evidence for demonic chimpanzees was so paltry? So what, you say? What does it matter?

It matters for your moral compass. If you believe that chimpanzees are naturally violent and murder their fellow chimps, then you can easily extrapolate to humans. You have evolutionary evidence for the belief that it is natural for humans do the same thing. What does this matter?

If you think violence comes from our genetic heritage, then the current murders and abuse that is rampant in our world makes sense-it's evolution's fault.

But this paradigm of demonic chimps (and humans) is false. The fossil records, archeology, anthropology, and primatology research say otherwise. As it turns out, neither humans or chimps evolved as hunters, as killers of their fellows.

If violence is not in our genetic heritage, what then? What is an alternative paradigm? Primates are the hunted, not the hunters. Hart and Sussman find considerable evidence for this and it fits the data better (e.g., how we are physiologically omnivores, not carnivores). Humans and other apes evolved as mostly unaggressive and peaceful, although they can become violent under particular circumstances (e.g., social stress).

If our evolutionary heritage is peacefulness, rather than violence, what does that mean for interpreting the current situation of rampant violence in our world? It means that our current cultures, societal practices and beliefs have created the violent humans we see around us. They are an aberration from our evolutionary heritage. As Douglas Fry shows in his volumes, "it's the culture, stupid." Some cultures breed violent citizens, others cultivate peaceful citizens.

That means we have ourselves to blame, not selfish genes, not evolution. And it means we can change the practices and beliefs that create our violent cultures.

The first place to start is with childrearing. Right now we are wringing out the capacity for peace in our children. Stressed and minimally cared for, undernourished emotional systems lead to depression and anxiety, isolation and loneliness. If neglected people don't become violent and callous towards others, they are violent to themselves but not reaching their peaceful potential.


Jane Goodall, (1986). The Chimpanzees of Gombe: Patterns of Behavior. Cambridge, MA: Harvard University Press.

Donna Hart and Robert W. Sussman (2009), Man the Hunted: Primates, Predators, and Human Evolution. Boulder, CO: Westview Press.

Margaret Power (1991). The Egalitarians, Humans and Chimpanzees: An Anthropological View of Social Organization. Cambridge, England: Cambridge University Press.

Richard Wrangham & D. Peterson (1996). Demonic Males: Apes and Origins of Human Violence. Boston: Houghton Mifflin.

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