Similar experiments have done the chimpanzees, orang-utans and other apes. Because they do not have the same vocal cords as humans, apes cannot be expected to speak. So the pioneers of this research, Allen and Beatrice Gardner of the University of Nevada, had the idea of teaching one of them sign language. In 1967 they obtained a one year old female chimpanzee named Washoe, and by 1971 had taught her to use American sign language, the method used by the deaf in the United States. She was repeatedly shown the signs and then was rewarded with a tickle or with food when she responded correctly. Washoe learned fast and soon knew a large number of words. She was eventually able to use 150 hand gestures.
Walking by a Lake one day, her trainer pointed at a dog. ‘What’s that?’, He asked in sign language. ‘Water bird’, said Washoe, apparently inventing her own word for ducks. Encouraged by this, other American scientists started training their own chimpanzees, using a range of different methods of communication. Some involved the identification of plastic shapes which symbolised, among other things, objects such as apples, or the trainers name. Others meant pressing different keys on a computer to communicate words or phrases. The result seemed to show that the chimps could indeed master language: they could respond to simple commands and use the language to ask for things.
Later, cold water was poured on the whole idea by another American psychologist, professor Herbert Terrace of Columbia University, New York. When Terrace analysed all Washoe two word phrases, he found that the word order was in fact a random. Washoe might just as easily have said bird water. Terrace also found that unlike human babies learning language, the chimps did not gradually increase the complexity of their sentences.
More recently, a pygmy chimpanzee called Kanzi has rekindled interest. Kanzi lives at the language research Centre near Atlanta, Georgia. His success in picking up the elements of language appears to show that pygmy chimpanzees have greater intellectual potential than gorillas, orang-utans and common chimpanzees.
Kanzi has been provided with a keyboard, linked to a computer. Each key is marked with the geometrical symbol which represents a word. As a baby, Kanzi played in the laboratory while his mother was taught to use the keyboard, and apparently picked up the skill by watching her. To the surprise of the scientists, Kanzi began using the symbols correctly at the age of two and a half, and by the age of three had acquired skills which common chimpanzees could not manage at the age of seven.
Picture Credit : Google