National Geographic : 1992 Mar
answered the basic questions: What is lan guage, how does it relate to other mental abil ities, and how does it differ from animal communication? F OR CENTURIES philosophers have argued that humanity's right to exploit nature derives from supe rior human awareness, as demon strated by language. But scientists cannot agree on whether other creatures share these abilities. Just as studies of the great apes have given insights into the origins of tool use and hunting, it would seem natural to expect that studies of our closest relatives could help answer questions about language. It has not turned out that way. "So far, any comparison between apes and humans is based on close to zero information about what apes say to each other in the wild," says the University of Michigan's John Mitani, who has been studying the calls of the various great apes. Chimps may ex change complex messages, but no one can do more than guess at the content of the infor mation they pass. A number of scientists have explored ape language capacities. In the mid-sixties psy chologists R. Allen Gardner and Beatrix T. Gardner suspected that chimps might have physical rather than mental difficulties in forming spoken words. They made a major breakthrough when they taught American Sign Language to an infant chimpanzee named Washoe. In 1967 Washoe signed "gimme sweet." Since then the history of the language experiments reads like a biblical genealogy, with some apes learning sign language while others studied invented token languages. Whether they used gestures or tokens, the apes took to language with style, not simply to identify objects but in what seemed to be all manner of provocative ways. The gorilla Koko referred to her nose by signing "fake mouth." The first time Washoe saw her own species, she signed "black bug." But what did it all mean? Was Washoe drawing on her vocabulary of more than a hundred signs to creatively describe some thing for which she had no sign, or was she merely summoning vague associations in the hope of a reward? Was Koko using language to be playful, or was researcher Francine Pat terson overinterpreting gestures? Were all the A wedge of liver from an anesthetized chim panzee (right) will be used in hepatitis experiments at the Southwest Foundationfor Biomedical Research in SanAntonio, Texas. In 1990 chimps here were protected against the AIDS virus by an experimental vaccine, now being tested on humans. Dressed in protective gear, Dennis Helmling hands out treats to relieve the boredom of20 chimps in the AIDS unit at LEMSIP, a lab at Sterling Forest, New York. He says: "They depend on us for communication and love. People should know that some of the drugs they take were tested first on chimpanzees."