Have you ever chuckled to smooth over an awkward moment? You’re in good company. Chimps also use laughter as a social lubricant, according to a study in press in Emotion.

Researchers from the University of Portsmouth in England spent months videotaping four captive chimpanzee colonies — with nine to 35 apes in each group — and captured 642 instances of laughter. About 82 percent of the time, the apes laughed spontaneously, producing a panting-like sound when a playmate surprised them by, for example, throwing a stick; 18 percent of the time, the chimps produced short chuckles in response to their playmate’s laughter.

The animals’ spontaneous laughter lasted about five times longer than the responsive laughs.

What were the apes trying to communicate through these chuckles? It’s possible that responsive laughter means, “I’m still having fun here,” says lead author Marina Davila-Ross, PhD.

“Laughter itself seems to prolong play, and play behavior is so important for young individuals, whether children or apes,” says Davila-Ross. “It helps young individuals develop their cognitive and emotional skills, and it helps form social bonds.”

Interestingly, the chimps in newly established colonies produced twice as many responsive laughs as chimps in well-established groups. This finding surprised the researchers, since they thought responsive laughter would be more of an expression of shared joy among familiar playmates. However, more laugher among relatively unfamiliar animals makes sense if the chimps are using chuckles to solidify friendships and alliances, Davila-Ross says.

“The apes aren’t just mimicking the expressions of other animals,” she says. “They are using emotional expressions in distinctive ways that give them important social advantages.”

—S. Dingfelder

Chimp laughter

In this video, you can see how chimps respond to each other through laughter. The male chimp begins laughing spontaneously 5 seconds into the video, and the female (the one on the tree) responds with a shorter bout of laughter 9 seconds later.