Is that chimp angry? Facial cues crucial

By Julie Steenhuysen

CHICAGO (Reuters) - The arch of an eyebrow or the curve of a lip tells chimps a lot about each other, a finding that may give scientists new understanding about the evolution of human communication, researchers reported on Friday.

Human faces can be easy to read, but sometimes people must look in different places on the face to get an accurate picture.

"What we know from humans is that even a single movement added to an expression can change the entire meaning," said Lisa Parr, director of the Yerkes National Primate Research Centre at Emory University in Atlanta.

"It can significantly affect the outcome of interactions," she said.

Until now, little research has been done on understanding how chimpanzees communicate through facial expressions, said Parr, speaking at an international conference of chimpanzee cognition at Chicago's Lincoln Park Zoo.

"There could be a whole realm of chimp communication we don't have the capability of understanding," she said.

Chimpanzees are humans' closest relatives, with just a 1.23 percent difference between the genetic codes of people and chimps. Scientists believe studying the behaviour of chimpanzees lends insights into human evolution.

FEAR OR SURPRISE?