Bonobos, one of humanity’s closest relatives, can tell when a human doesn’t know something and steps in to help — a cognitive ability never before identified in nonhuman apes, a study found.
Researchers tested this in a game with three bonobos (Pan paniscus) living at Ape Initiative in Iowa, U.S. One bonobo, Kanzi, 44, is famous for his participation in numerous studies and an ability to play Minecraft.
The researchers wanted to see if the apes were able to use intuition to pick up on subtle nonverbal cues and recognize when a human lacks knowledge.
The game went as follows: the bonobos watched as a treat, like a grape or piece of cereal, was hidden under one of several cups. Sometimes the experimenter saw where the treat was placed, but sometimes not. For the bonobo to get the treat, the experimenter had to guess the correct cup, and the bonobos could help by pointing.
The three bonobos pointed more often and more quickly when their partner didn’t know where the food was, but held back when the experimenter was already aware, the results showed.
“We found evidence that they can not only track ignorance, but can also modify their behavior accordingly,” the lead author Luke Townrow, a comparative social cognition researcher at Johns Hopkins University, told Mongabay by phone. “This is a milestone.”
Prior to this study, there was no consensus among scientists about whether apes might possess this ability.
Alexander Piel, an evolutionary anthropologist specializing in primates at University College London, who wasn’t involved in the study, described the findings as “exciting” and said they raise questions about whether bonobos can demonstrate this ability in other contexts.
“What I’d like to see next is: can they do this with their own species in the wild?” Piel told Mongabay in a video interview. “Because otherwise, we risk asking what humans have taught apes, rather than what apes naturally do.”
Bonobos are an endangered species endemic to the Democratic Republic of Congo, where they face threats from deforestation, poaching and the pet trade. At least 15,000 to 20,000 individuals live in Salonga National Park in the DRC, with thousands more likely living in nearby forest areas. A handful of others are kept in zoos and research facilities around the world.
Piel noted that the study involved only three bonobo individuals, all of whom have spent their lives doing cognitive experiments. “In some ways, it’s like testing the Einsteins of bonobos,” he said.
Still, he acknowledged the broader significance of research that blurs the boundaries between humans and other species.
“These results continue to challenge human uniqueness,” Piel said. “One by one, the things we long held as distinct to us are at least being blurred, if not being completely disputed.”
Banner image: Kanzi, one of the bonobos who participated in the experiment, can intuit when humans know something. Image courtesy of Ape Initiative.
