One study shows that male bonobos engage in violence more often, though less intensely, than male chimpanzees

Phie Jacobs, Bonobos, the ‘hippie chimps,’ might not be so mellow after all, Science, April, 12, 2024.

Chimps (Pan troglodytes) and bonobos (Pan paniscus) are the closest surviving relatives of modern humans. That makes them interesting subjects for scientists studying how aggression evolved in our own species. But the two apes are very different in their behavior. Chimps are patriarchal, forming all-male coalitions that patrol their territory; they react violently when they happen upon an outsider or neighboring clan. “Chimpanzee intergroup encounters are not possible,” Mouginot explains. “They will kill each other.”

Bonobos—which some have called “hippie chimps”—are far more peaceful, says Brian Hare, an evolutionary anthropologist at Duke who wasn’t involved in the new research. Their societies are dominated by females, and amicable interactions between communities are commonplace—and frequently marked by displays of enthusiastic sexual activity. And although bonobos are no strangers to conflict, scientists who study the apes have never witnessed a lethal encounter. As far as we know, Hare says, “no bonobo has ever murdered another bonobo.” [...]

Field researchers tracked 12 male bonobos from three communities—from the moment they woke until they settled down for the night—at the Kokolopori reserve, located deep within the Democratic Republic of the Congo. They did the same with 14 male chimps from two communities at Gombe Stream National Park in Tanzania. Every time an ape attacked or charged an adversary, or was on the receiving end of such aggression, a researcher was there to document it.

The results, Mouginot says, “really came as a surprise.” Overall, male bonobos turned out to be about three times as likely as chimps to engage in aggressive behavior. Although none of the encounters were lethal—and the team didn’t track the severity of injuries—bonobos weren’t afraid to push, hit, and bite their foes. Their aggression didn’t appear to be a turn-off for female bonobos, who actually preferred to mate with aggressive males. [...]

But whereas male chimpanzees frequently ganged up to or defeat rivals or bully females, bonobo males mainly participated in one-on-one fights and rarely attacked members of the opposite sex. In fact, males were far more likely to be on the receiving end of violence from groups of aggressive, dominant females.

There's much more at the link.

H/t Tyler Cowen. 

More –

• about the bonobos in the NYTimes. 
• The original research: Differences in expression of male aggression between wild bonobos and chimpanzees.