Brian Hare admits he was kind of rooting for the bonobos.
“You normally aren’t hoping for a result,” says Hare, associate professor of evolutionary anthropology, who with Chris Krupenye Ph.D. ’16 studied interactions preferred by bonobos at the Lola ya Bonobo Sanctuary in the Democratic Republic of the Congo. “But I kind of hoped that maybe they would like the helper,” he admits. Bonobos—with chimps, the closest genetic relatives to humans— are famous for being our kinder, less-aggressive cousins. “There’s this public perception of them as the hippie ape,” Krupenye says from his current position as Marie Sklodowska-Curie Fellow in the School of Psychology and Neuroscience at the University of St. Andrews in Scotland. “And that’s not true.”
Evidently not. For a study published in Current Biology in January, Hare and Krupenye had the bonobos watch animated videos in which a little Pac-Man-type character can’t get up a slope. In one version a little triangle character comes and helps, pushing it up; in another version a little square hinders it, pushing it back down. Then testers offered bonobos two treats, one beneath a little paper triangle and the other beneath a square. The bonobos preferred the food beneath the unhelpful square. In a similar trial, bonobos saw humans act out a situation in which one person dropped a toy. In one version another person helped retrieve the toy; in another someone snatched it away. Then the people offered food to the bonobos, and again the apes preferred the hindering people.
Try not to be too disappointed, though; Krupenye doesn’t think meanness was the takeaway. “They saw the hinderer as dominant,” he says of the bonobos. “And they were attracted to that individual as a result.” Hare explains it as an example of what is called winner support. In social conflicts where two individuals work against each other and a third joins the interaction, he says, “the third individual tends to join the one that’s winning.” In the study, “I think they’re seeing this guy is winning and that guy is losing, and ‘I like the guy who wins.’
“I think they view the exact same scene completely differently than we do.”
In fact, says Krupenye, bonobo viewing of the scene is an underreported aspect of the study. “The media is focusing on the nature of their choices, but another key finding is their attention in general and that they were able to extract social information from watching—social information that was important to them. When they were watching interaction between actual humans, when things got heated up, they would get really interested. They would vocalize.”
The nature of that interest in social interaction opens the door to future research, Hare says. “We had artificial cartoon animation,” he says of the studies, “and we had interactions between humans. But we didn’t have anything between bonobos.” That is, if the bonobos see interactions between conspecific individuals—those of their same species—they might react differently than they did to cartoon videos or interactions between members of other species. He’s heard from colleagues making that point. “I have received fascinating and collegial but very critical e-mails from colleagues I respect saying, ‘I think you guys got it wrong.’
”Just the same, if the bonobos preferred the helpers, that would be big news. “It would be fascinating—and a challenge to a number of hypotheses about human development and evolution,” Hare says. Humans seem to be unique in our preference for kindness over dominance, which Krupenye notes has been demonstrated in infants as young as three months old. That preference for helping seems to be part of how we can function in companies and other large groups. In our preference for kindness and cooperation, humans seem to remain evolutionarily unique.