The researchers analyzed more than 1,200 interactions with groups of chimpanzees and bonobos at zoos and found that they often exchange glances or exchange gestures to share their intentions about social interactions. These gestures included touching each other, holding hands, and even nodding.
Scientists say the ability of apes to signal and say goodbye indicates something far greater than courtesy. It shows that chimpanzees and bonobos can communicate a mutual sense of obligation to each other.
“In humans, this (sense of mutual obligation) is a testament to joint commitments,” said the study’s lead author, Raphaela Heesen, a postdoctoral researcher at the University of Durham in the UK. “This supports all kinds of joint interactions, including small-scale interactions, for example, if you dine with your friends or large-scale, such as large projects.”
“It’s like the tail of our success as a species, and that work is also present in bonobos and chimpanzees,” Heesen told CNN.
Unlike previous studies, the researchers proposed that joint commitments are not only based on a sense of obligation, but also on the process of establishing agreement with each other and agreeing that it has been fulfilled. That’s why Heesen says it’s significant that monkeys communicate with each other when they intend to start and end interactions, such as playing or preparing.
“When they were iterating with a good friend, they produced shorter input and output phases … and often didn’t even communicate at the end of an interaction,” Heesen added. “And we know that from our daily lives too, don’t we? If we interact with a good friend, we don’t have that kind of courtesy.”
“We used to think that humans were the only species that coordinated the entry and exit phases of interactions,” he said. “It has not been systematically studied whether other species are as well off as we are. We know that other species initiate interactions, so the ‘entry phase’ is common among other animals.”
Clare Redfern, a senior bonobo keeper at the Twycross Zoo in the UK who was not affiliated with the study, said scientists and zoo keepers have long known that apes greet each other, but new research is improving their understanding of animal behaviors.
“From the first observations of these animals in the wild, it was obvious that these species were greeting each other; however, now that more is being studied about the species, researchers have adopted more subtle behaviors,” Redfern said. on CNN. an email. “The behaviors of bonobos are much more subtle than those of chimpanzees, whose gestures are more obvious, so some smaller gestures can be easily lost, as they are subtle and occur very quickly.”
“The gestures we make [commonly] notice that our bonobo groups extend their hands and also feature body parts, ”Redfern said.
He added that “eye contact and gaze are extremely important in bonobo behavior, which allows individuals to establish a closer bond between them.”
He sTudy’s authors also say that more research is needed on the origins and evolution of joint engagement behaviors in both humans and other species.