Sign Language Studies Show Apes Expressing Their Emotions

Apes who communicate through sign language talk about many of the same things that humans do, right down to swearing, researchers say.

Talking apes usually speak in incomplete sentences, much like humans, said Roger Fouts, a psychology professor at Central Washington University in Ellensburg, Wash.

Fouts works mostly with chimpanzees, and he says they make simple sentences.

He said his studies show 88% of the conversations among chimpanzees using sign language center around matters such as getting along with each other, playing and grooming.

“If the play gets rough, you might actually get someone blaming someone else, someone claiming to be good,” Fouts said.

Fouts and Joanne Tanner, a volunteer researcher with the Gorilla Foundation in Woodside, about 30 miles south of San Francisco, discussed their research Wednesday before a sell-out crowd at UC San Diego.

Fouts said one of five chimps in his study has used sign language since she was a baby. The chimp, Washoe, today uses both sign language and ape language.

“We are curious whether the signing (use of sign language) acts to decrease the level of aggression,” Fouts said. “If you can say things, express them with words, you don’t have to act them out.

More Specifics

Sign language makes communication more specific, Fouts said. For example, a chimp may turn his back to another to get himself groomed. But sign language allows the ape to say specifically where he wants to be groomed.

Tanner, a violinist with the San Jose Symphony Orchestra, volunteers one day a week at the Gorilla Foundation.

Tanner lectures on the extensive work done with two gorillas, Koko and Michael.

Koko, 14, became internationally known last year when newspaper pictures showed her mourning the death of the pet kitten she had named “All Ball.”

Koko, who has a 500-word vocabulary in sign language, cried when told the cat had been run over by a car.