Chimpanzees and Sign Language: Darwinian Realities versus Cartesian Delusions

Abstract

dr. fouts began his lecture with the story of how he and his wife Deborah became involved with Washoe—the first non-human to acquire the signs of American Sign Language (ASL). Project Washoe began in 1966 with Drs. Allen and Beatrix Gardner in Reno, Nevada. There had been other experiments that attempted to get chimpanzees to speak. These experiments were not successful due to anatomical and neurological differences between humans and chimpanzees. (Fouts showed some video of the chimpanzee Vicki trying to say the four words she had learned—mama, papa, up, cup.) Part of the issue is the construction of the chimpanzee’s vocal box while another part of the issue is that chimpanzee vocalizations are tied to their limbic system—vocal utterances are triggered by things like excitement and fear. This is true of some human vocalizations as well—hitting your thumb with a hammer often causes utterances you might wish to suppress but which come out of your mouth anyway. Examples of chimpanzees trying to suppress such vocalizations have been observed as well. Fouts told the story of Jane Goodall, in some of her field work in Tanzania, realizing that allowing access to feeding stations could often lead to fights among the chimpanzees. So, she limited access to the food to times when only one chimpanzee was present. One particular male chimpanzee would often gesture to the rest of the chimpanzees and lead the group away from the feeding station and then return later on his own. When he got access to the food, however, he would vocalize and the other chimpanzees would return. Unable to suppress these vocalizations, he was observed covering his mouth with his hand. Taking into account such facts about chimpanzee physiology, and the growing realization that chimpanzees use gestures as part of their repertoire of communication strategies, the Gardners decided to construct an experi-