Bonobos are just as aggressive as chimps, but there’s a key difference — the female bonobos
“Hippie” bonobos are just as aggressive as “warrior” chimpanzees, a new study suggests. However, the findings also reveal some key details about the gender behind the assault. Female bonobos were more likely to attack males, while male chimpanzees were more aggressive toward females. They found that aggression between females in both species was significantly lower.
The work focused on captive animals in zoos, so it may not apply to wild bonobos and chimpanzees, but it adds to a growing body of recent research suggesting that bonobos are not as peace-loving as previously described.
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Bonobos (Pan paniscus) And chimpanzees (Pan troglodytes) are our closest living relatives. The two species are geographically separated by the Congo River in Africa and evolved from a common ancestor between 1.5 and 2 million years ago.
Although they are closely related, chimpanzees and bonobos look and behave differently. Bonobos are smaller, with a more slender buildand sex differences are less pronounced than in chimpanzees. Bonobo communities are led by women’s coalitions; this is considered a strategy for females to gain power over larger males. On the other hand, chimpanzees have men at the top of their hierarchy.
Aggression is an important social behavior among great apes because it helps them protect their territory, identify mates, assert dominance, and secure resources. This aggression can range from vocal expressions of anger to physical attacks.
In the past, bonobos were considered the peaceful “hippie” cousins of chimpanzees, as they were considered less warlike and less warlike. more likely to use sex to resolve conflict. But recent studies began to overturn this idea. In a recently reported incident, five wild female bonobos viciously attacked a male in the Democratic Republic of Congo.
In the new research, published Wednesday March 11 in the journal Scientific advancesresearchers show that bonobos are just as aggressive as chimpanzees, but they target males and females differently.
Little difference in overall aggressiveness
The team analyzed how 22 groups of chimpanzees and bonobos based in zoos in Europe interacted. A researcher sat in front of the enclosure and recorded every act of aggression, ranging from shouting to physical violence, that occurred throughout the day. The team spent two to three months in each zoo, recording a total of 3,243 cases of aggression from all monkeys aged over 7 years. Seven years old is the youngest age at which researchers have recorded a male bonobo breeding, Staes said.
They found that there were 1,368 cases of directed aggression from bonobos and 1,875 from chimpanzees. About a third (1,193) of the cases were “contact” assaults, meaning there was physical violence between individuals rather than simple shouting or other less violent forms of aggression. Once the data was controlled for sex, relationship and context, there was little difference in overall aggression between chimpanzees and bonobos.
“You don’t find chimpanzees to be more aggressive,” Staes said. “Bonobos are just as aggressive.” Among chimpanzees, males were mainly responsible for conflicts. Male and female bonobos, on the other hand, were equally likely to fight. “There are no gender differences in bonobos, which surprised us a little,” Staes said.
However, there were differences in the gender targeted. Male chimpanzees were aggressive toward females and other males, and they were also more likely to become physically violent. Female bonobos were more likely to be aggressive towards male bonobos. Although there is male-male aggression among bonobos, there is rarely female-female aggression, Staes said.
But bonobos are better at making up, she said, adding that in a future study the team plans to describe how different groups resolved conflicts.
There were also marked differences between levels of aggression among groups of bonobos in different zoos – even more so than among chimpanzees. “Our findings contribute to a growing body of evidence suggesting that behavioral patterns in Stoveincluding aggression, may be more influenced by group identity than by species-wide traits,” the authors wrote.
Zoos offer an interesting perspective on monkey behavior. Some researchers claim that chimpanzees are more warlike because the food was less available on their side on the Congo River and they had to compete with gorillas for resources. Vice versa, bonobos had more food and fewer predators.
In zoos, these environmental factors no longer come into play. “The main advantage is that you remove the two species from their ecology and you actually get behavioral differences due to, for example, genetic changes that have occurred since they were separated,” Staes said.
Sonya Pashchevskayabehavioral ecologist at the Max Planck Institute of Animal Behavior in Germany who was not involved in the research, said she welcomed the new findings. “This study is particularly important in light of the notion of ‘hippie’ bonobos, famous for their origins in captivity,” she told Live Science. “It’s great to see the myth methodologically challenged in such a context and with multiple groups involved.”
“Aggression, as a means of resolving conflict, is a normal part of life,” Pashchevskaya said. While chimpanzees are more likely to take violence to extremes, bonobos may “reserve real violence for the worst dangers.”
New information about bonobo aggression could provide more clues about conflicts between our closest relatives. “Although conflict is inevitable,” Pashchevskaya said, “there are various aggressive expressions, and emanating from both sexes.”
Roth, T., Edwin, VL and Bryon, E. (2025). Replication data for: Chimpanzees are not more aggressive than bonobos, but target sexes differently [Dataset]. In DataverseNL. https://doi.org/10.34894/c7vbhl
