Born Into Guerilla Warfare—Chimpanzees Reveal a ‘Killer’ Instinct in New Study

In humans, death is often an outcome of two drastically different means to an end: Love and War. However, it has always been thought that we stood alone on battlefields. While other animals typically engage in deadly fights or disputes over a fertile female or the chance to procreate, it has long been understood that calculated war-like murder is a trait only humans could have. That is, until we looked into the trees.

In the 1970's world-renowned primatologist Jane Goodall made a discovery that quickly changed our understanding of guerilla warfare. While studying two groups of chimpanzees in the forests of Gombe, Goodall discovered that the lesser species of ape chimpanzees were not only capable of murder, but were violent warring creatures by instinct. But her theories were largely misunderstood by the science community.

She witnessed factions dividing, strategized war between two groups of chimps. And that wasn't even the shocking part. The brutality exhibited by the chimps was something both gory and human-like at once. Recorded cases of chimpanzee violence grew to include heinous acts such as castration of rival clan members and even disembowelment, something that researchers believed had to have been an influence humans had exhibited on the impressionable creatures.

We had taught them sign-language and how to act in films, so why couldn't we have taught them the art war?

But as with Goodall, a new study released this week in the journal Nature proves that the inner "killer" in chimpanzees is something a bit more instinctual. Analyzing over fifty years of data collected from 18 distinct chimpanzee communities, a team of 30 international primatologists investigated the origins and factors that led to the war-time murders of 152 chimps in particular. What they found was that the majority of chimpanzees attributed with violence were males and many of the murders were results of natural behavior: shows of power and dominance over competitors that have arisen as an evolutionarily derived trait across many species.

"Wild chimpanzee communities are often divided into two broad categories depending on whether they exist in pristine or human-disturbed environments" co-author and research fellow for the Conservation of Apes at Lincoln Park Zoo in Chicago David Morgan, Ph.D. says. "In reality, however, human disturbance can occur along a continuum and study sites included in this investigation spanned the spectrum. We found that human impact did not predict the rate of killing among communities."

While the research data may not indicate a direct human influence leading to the murderous acts of aggression, the fact remains that the chimpanzees are capable of such warring actions. And though the researchers hope that in studying chimps at war we can reveal a bit more on the origins of our own "killer instinct", continued research in the area will be much more vital to the protection and conservation of chimpanzees in captivity.

"The more we learn about chimpanzee aggression and factors that trigger lethal attacks among chimpanzees, the more prepared park managers and government officials will be in addressing and mitigating risks to populations, particularly with changing land use by humans in chimpanzee habitats" Morgan says.