Chimpanzees and bonobos (tailless monkeys) signal “hello” and “goodbye” when in contact, much like humans, a new study finds.
In other words, these apes have 99% of the same DNA as humans, politely greet each other when they meet, and say goodbye, just like humans. To date, this behavior has not been recorded in any species other than humans, the researchers say.
“Our findings suggest that two great apes often go through the same process as humans when performing greetings and goodbyes,” the researchers wrote in the study, published online in the journal iScience. 11/8.
Apes also hug and kiss when they meet
The apes don’t just sound the equivalent of asking “What’s the matter?” in social meetings. Rather, they have a wide range of nonverbal cues. This also happens to humans. For example, when people meet, they often point their bodies toward each other, look at each other, and show intent to touch, hug, or kiss before starting a conversation. At the end of an interaction, people often turn away from each other.
To determine whether chimpanzees and bonobos practice these behaviors, the researchers analyzed 1,242 hominin interactions at zoos, and they found that these primates often communicate with each other. with gestures including staring and touching, holding hands, or headbutting – before and after encounters or play. Of the two, however, bonobos are definitely the more polite, greeting each other more often than chimpanzees.
At the beginning of the interaction, the bonobos exchanging signals met and looked at each other in 90% of the cases, while chimpanzees did so in 69%. During parting, bonobos also outperformed chimpanzees, exhibiting parting behavior 92% of the time, while chimpanzees exhibited it in 86% of interactions.
The team also investigated whether these behaviors changed when the apes interacted with each other. They found that the closer the bonobos were to each other, the shorter the duration of their behavior. Lead researcher Raphaela Heesen, a postdoctoral researcher in the department of psychology at Durham University, UK, says this is not too different from human behavior.
The society of chimpanzees is hierarchical, bonobos are egalitarian
This may be because, compared with hierarchical chimpanzee society, bonobos are largely egalitarian, socially tolerant, and emphasize friendship and alliances between children and their children, the researchers say. mother-child relationship. It, therefore, makes sense that the social relationships of bonobos would have a strong impact on saying hello and goodbye.
Meanwhile, there was no significant effect of hierarchical differences on the presence at meeting and parting in both ape species.
The findings suggest that perhaps a common ancestor of apes and humans practiced similar behaviors, the researchers say.