Chimps speak universal language of laughter

A study of baby chimps has found that they smile readily at human handlers within a month of birth and laugh out loud when tickled, just like human babies.

Kim Bard of the University of Portsmouth said smiling in a young chimp was central to communication. "We see smiling in response to adult smiles, and positive interactions as early as the first 30 days of life," she said.

"Chimpanzees appear to express similar emotions to infant humans, although some of them might look a little different. All chimpanzee infants smile and felt happy within the first three weeks of life," she said.

She said a happy chimp "smile" was distinctly different from an unhappy grimace. "Their mouth is open, and when you tickle them, they laugh. If they grimace and you try to tickle them they might bite you."