The origin of humor in great apes: teasing each other.

Bonobos, orangutans, gorillas, and chimpanzees all poke, tickle, and even steal from their companions as a form of teasing. Understanding the mischievous behavior of these apes could help biologists uncover the origins of the human sense of humor.

Previous research They found that chimpanzees can use painful teasing, or harassment, to reinforce their hierarchical position. But he says teasing can also be a form of play and fun when the right balance of fun and aggression is struck. Isabel Romer at the Max Planck Institute for Animal Behavior in Germany.

“So far, the playful nature of teasing has not been systematically studied,” she says. “Therefore, our goal was to identify and create standards for play that teases great apes.”

To do so, Romer and her colleagues studied five species of great apes, bonobos (Pampan Niscus), Sumatran orangutan (pongo abeli), Western Gorilla and Eastern Gorilla (gorilla gorilla and gorilla beringay) and chimpanzees (pan-troglodytes). There were a total of 34 great apes, all housed in the zoo.

The researchers recorded 504 social interactions between individuals from 75 hours of video footage. Of these, 142 were classified as playful teasing, and included 18 acts such as pecking, hitting, hair pulling, impeding movement, and stealing.

“Teasing is characterized by an element of provocation,” Romer says. “It usually starts with a teaser, is often one-sided, and repeats itself over and over again.”

Researchers found that teasers tended to stare at the target's face immediately after the action. This suggests that the teaser was anticipating the reaction. If there is no response from the target, the teaser will usually escalate the teasing by poking the target further.

One of the most important signs that the teasing is playful rather than hostile is that it usually takes place in a calm and comfortable environment. “During the interaction, participants tended to relax,” Romer says.

Cases of theft were considered to be play if the item provided no obvious benefit to the teaser or if the teaser lost interest in the item shortly after pinching it.

“We found that playful teasing is present in all four species of great apes,” Romer said. Like play in general, this behavior can also help build relationships between groupmates and test social boundaries, she says.

Romer added that the last common ancestor between humans and other great apes likely also playfully teased, which may have been a precursor to our love of jokes. Ta.

“Studying great apes is important for understanding which cognitive and behavioral traits humans share and likely evolved in a common ancestor millions of years ago.” says the doctor. Christopher Krupenier at Johns Hopkins University in Maryland. “This study provides exciting evidence that all great apes appear to engage in playful teasing behavior, and also points the way for future research in other species.”