THURSDAY, March 3, 2011 (HealthDay News) -- Just like humans, chimpanzees mimic the laughter of others in order to strengthen social bonds, say researchers who studied 59 chimpanzees living in four groups in a sanctuary in Zambia.
Their finding suggests, they say, that chimpanzees and other great apes have a more complex social use of expressions than previously thought.
"We found that their responsive laughter shows a similarity to the conversational laughter of humans," the study's lead author, Marina Davila-Ross, a behavioral biologist at the University of Portsmouth, in England, said in a university news release. "Both are shorter than spontaneous laughter, and both seem designed to promote social interaction."
"These sorts of responses may lead to important advantages in cooperation and social communication ... qualities that help explain why laughter and smiles have become integral tools of emotional intelligence in humans," she added.
The study, being published in the journal Emotion, also found that chimpanzees in newer groups mimic the laughter of their companions more often than those in established groups, where the chimpanzees know one another well.
The Jane Goodall Institute of Canada has more about chimpanzee behavior.