• Posted February 14, 2024

Are Apes Comedians? Study Says Yes

Being a class clown is something that humans likely inherited from their ape ancestors millions of years before the first banana-peel prank, a new study claims.

Everyone's seen kids tease one other, whether they're poking, pulling hair or engaging in the time-old ritual of "I'm not touching you!"

This sort of playful teasing also occurs among humans' great ape cousins, a research team has found. 

Orangutans, chimpanzees, bonobos and gorillas all engage in different forms of playful teasing, researchers report Feb. 13 in the journal Proceedings of the Royal Society B.

Like humans, ape teasing is provocative and persistent, and includes elements of surprise and play, researchers said.

"It was common for teasers to repeatedly wave or swing a body part or object in the middle of the target's field of vision, hit or poke them, stare closely at their face, disrupt their movements, pull on their hair or perform other behaviors that were extremely difficult for the target to ignore,"said senior researcher Erica Cartmill, a professor of anthropology with Indiana University.

Because all four species of great apes shared this behavior, it's likely that humans gained the prerequisites for humor through evolution at least 13 million years ago, researchers concluded.

Playful teasing is a known precursor to full-fledged jesting and humor in human development, researchers said in background notes.

Babies display playful teasing behavior as young as 8 months old, before they have said their first words, researchers said. A baby might playfully offer a toy to their mom then pull it away, or playfully disrupt another infant's activities to get their attention.

Researchers decided to see if apes have this in common with humans.

"Great apes are excellent candidates for playful teasing, as they are closely related to us, engage in social play, show laughter and display relatively sophisticated understandings of others' expectations,"said lead researcher Isabelle Laumer, a postdoctoral researcher with the Max Planck Institute of Animal Behavior in Germany. 

For the study, researchers analyzed spontaneous social interactions among apes that appear to be playful, mildly harassing or provocative.

The team identified 18 distinct teasing behaviors among apes, mostly to provoke a response or attract attention.

As in humans, teasing differed from play in several ways, researchers noted.

"Similar to teasing in children, ape playful teasing involves one-sided provocation, response waiting in which the teaser looks towards the target's face directly after a teasing action, repetition, and elements of surprise,"Laumer said in a Max Planck news release.

The team noted that primatologists like Jane Goodall have previously noted similar behaviors in chimpanzees, but this was the first effort to systematically study playful teasing.

"From an evolutionary perspective, the presence of playful teasing in all four great apes and its similarities to playful teasing and joking in human infants suggests that playful teasing and its cognitive prerequisites may have been present in our last common ancestor, at least 13 million years ago,"Laumer said.

"We hope that our study will inspire other researchers to study playful teasing in more species in order to better understand the evolution of this multi-faceted behavior,"she added. "We also hope that this study raises awareness of the similarities we share with our closest relatives and the importance of protecting these endangered animals."

More information

Harvard Medical School has more about humor and the human brain.

SOURCE: Max Planck Institute of Animal Behavior, news release, Feb. 13, 2024