Cannibal Chimps and Their No-Good, Truly Awful Headlines

By Allison Mills | Published

It was just a little bit, the primatologist said. But a little bit of cannibalism goes a long way in shaping headlines (and humans' views) of chimpanzee behavior.

Nature documentaries might as well be HBO shows. Or at least that's how humans would like them to be. Most of us prefer the Circle of Life's drama over the tedium of what actually happens in everyday life, and the way we write about that drama reveals deeply ingrained biases about how we perceive and judge animal behavior. It comes down to how humans perceive and judge themselves.

In the chimpanzee research community, this tension drives to debates about aggression versus affiliation says Kelly Boyer Ontl, a visiting assistant professor in the Department of Social Sciences at Michigan Tech. Ontl, who has studied chimp groups in West Africa, explains that some researchers think chimpanzee interactions are inherently violent and self-serving—full of conflict—but others think that their behavior is inherently diplomatic and group-focused—based on cooperation.

Often, aggression versus affiliation (with a heavy emphasis on the former) plays out in the headlines about chimp behavior. Take, for example, the headlines throughout this story. They're all based on a study that came out in January; one that Ontl contributed to and her adviser, Jill Pruetz from Iowa State University, led.

If it bleeds, it leads, right?

Trees are bitten more often than fellow chimps.
Trees are bitten more often than fellow chimps.
"Chimpanzee Clan 'Goes Ape': Chimps Attack, Brutally Murder and Feast on Ex-Leader In Angry Fit—And No One Knows Why"Inquistr

This article from Inquistr, immediately backtracks in the opening paragraph. The main caveat being: killing—and certainly cannibalism—are rare amongst chimps. Ontl cites a Nature paper that documents lethal aggression in 15 chimp communities over 50 years: there are 152 total, and most are conflicts between communities in which a single unlucky chimp, from one community, gets mobbed by chimps from another community (the median ratio is eight to one; hardly a fair fight). The attack documented in Pruetz and Ontl's research is one of only nine recorded killings during the past five decades that happened within a chimp community – meaning these attackers knew their victim.

"Scientists Show That Chimps Will Murder and Eat Their Dictators"Inverse

The incident described by Inverse here comes down to the chimp's backstory. 

Ontl is one of the researchers who followed and recorded the activity of former-alpha male Foudouko and his community, the Fongoli chimpanzees in Senegal. She remembers clambering through the forest watching the chimps forage—almost a year after Foudouko’s fall from dominance and subsequent disappearance—when she saw a strange, but familiar gray-backed chimp being run off by the group. It was Foudouko, previously noted as a heavy-handed and controlling alpha in his prime, now exceptionally skittish and an outcast. Ontl's brief sighting was one of several that spanned five years after he was ousted by a group of younger males.

What's really fascinating—at least from the scientific perspective that focuses on cooperation—is the role played by Mamadou, Foudouko's former second-in-command and only friend in exile when Foudouko was forced from the group. But instead of abandoning him, Mamadou kept a tentative connection going, meeting at the edges of the group, which Ontl observed the first day she saw Foudouko and followed him through the woods for a time.  

He attempted to return to the group in 2013. It didn't work out, though not quite as the Independent summarized in its headline.

"Chimpanzees Overthrow, Kill and Then Eat Their Tyrannical Leader: The Experienced Anthropologist That Led the Study Said She Was Left 'Disturbed' by the Behaviour"The Independent
Ontl has observed several chimp groups in West Africa, including the Fongoli chimps.
Ontl has observed several chimp groups in West Africa, including the Fongoli chimps.


Let's focus on a moment on the choice of verbs so far. Overthrow. Kill. Murder. Eat. Feast. What Ontl says we're missing in the discussion is the role of intentionality.

"What it really comes down to is the intensity of the attack," she says, explaining escalating aggression is not the same as intending to kill. "We tend to simplify animal behavior, particularly primate behavior, to create stories about ourselves as humans."

In other words, a vicious animal attack is a way to both anthropomorphize the Fongoli chimps while simultaneously setting human societies above such beastly acts.

"In Rare Killing, Chimpanzees Cannibalize Former Leader: The rare incident may have been all about sex, researchers suggest. Warning: graphic content"National Geographic

Of course, National Geographic does a great job putting Foudouko's death in context—and it helps that Pruetz is a National Geographic Society grantee—but even this headline, which almost hits the mark, is still too easy to read through a human-made lens.

Grooming is an important part of chimp society; so are secret handshakes.
Grooming is an important part of chimp society; so are secret handshakes.


Because let's be honest, what we want the research to tell us about is why humans sometimes attack one another and occasionally succumb to cannibalism. That's all important information—and even if it doesn’t stop wars, it would at the very least shed some light on the entertainment industry.

Except that notion is wrong in terms of the science, Ontl points out.

Humans and chimps simply aren't related enough. Evolution lesson in a nutshell: Humans are not descendants of chimps, rather we share a common ancestor and evolved separately. It's like saying you can't sort out great-grandma Winny's wild youth by observing cousin Fred now. Which all together means, no, better understanding lethal aggression in chimps won't explain away the base nature of human homicides or our obsession with the brutality of shows like Game of Thrones.

What lethal aggression in chimps can tell us is about the evolutionary advantages and differences of humans and chimps separately—and what they may have meant for our common ancestor—as well as how environmental pressures like increased contact with humans and changes in habitat can change chimp behavior. Lethal aggression in chimps is more likely a mirror of current human activities than it is a glimpse into an alleyway crime scene or Medieval battlefield or Neanderthal cave.

"Cannibal chimps killed and ate their former leader - probably over sexOne expert described the rare case of chimps turning on their own pack as akin to an episiode of The Sopranos"Mirror

Only a couple last bites to take, finishing with the Mirror. Let's talk chimp cannibalism and sex.

In this instance with the Fongoli chimps, sex is clickbait's safe word for environmental and social pressures—the chimp community is highly skewed male, which creates a lot of … tension. It's less of a Sopranos soap opera and more like knowing the juicy town gossip. Same goes for how we talk about cannibalism.

"We make chimps, gorillas, Neanderthals into these gruesome characters in order to separate humans from the animal world," Ontl says. "They're making a big deal in these headlines as if cannibalism is a thing that humans never do—those crazy, wild animals!"

Yet cannibalism—stomach turning as it is to many—simply isn't as rare as we might expect across the board, whether that's among humans, chimps, fish, or salamanders. Just check out Cannibalism: A Perfectly Natural History and read about how leeching wasn't the only bizarre medicine of the Middle Ages.

And if you're still hungry for more, here's also an oldie but a goodie from The Atlantic to chew on for dessert. Bon appétit.

"Does Chimp Warfare Explain Our Sense of Good and Evil?"The Atlantic
The Fongoli chimps are highly skewed male, which creates more mating pressure and competition in the group.
The Fongoli chimps are highly skewed male, which creates more mating pressure and competition in the group.

Michigan Technological University is a public research university, home to more than 7,000 students from 54 countries. Founded in 1885, the University offers more than 120 undergraduate and graduate degree programs in science and technology, engineering, forestry, business and economics, health professions, humanities, mathematics, and social sciences. Our campus in Michigan’s Upper Peninsula overlooks the Keweenaw Waterway and is just a few miles from Lake Superior.