A Chicago Style Sample Paper
March 22, 2001
Apes and Language: A Literature Review
Over the past thirty years, researchers have demonstrated that the great apes (chimpanzees, gorillas, and orangutans) resemble humans in language abilities more than had been thought possible. Just how far that resemblance extends, however, has been a matter of some controversy. Researchers agree that the apes have acquired fairly large vocabularies in American Sign Language and in artificial languages, but they have drawn quite different conclusions in addressing the following questions:
1. How spontaneously have apes used language?
2. How creatively have apes used language?
3. Can apes create sentences?
4. What are the implications of the ape language studies?
This review of the literature on apes and language focuses on these four questions.
How Spontaneously Have Apes Used Language?
In an influential article, Terrace, Petitto, Sanders, and Bever argued that the apes in the language experiments were not using language spontaneously but were merely imitating their trainers, responding to conscious or unconscious cues. Terrace and his colleagues at Columbia University had trained a chimpanzee, Nim, in American Sign Language, so their skepticism about the apes’ abilities received much attention. In fact, funding for ape language research was sharply reduced following publication of their 1979 article, “Can an Ape Create a Sentence?”1
1. Haley Terrace et al., "Can an Ape Create a Sentence?" Science 206 (1979): 894.
In retrospect, the conclusions of Terrace and others seem to have been premature. Although some early ape language studies had not been rigorously controlled to eliminate cuing, R. A. Gardner and B. T. Gardner were conducting double-blind experiments that prevented any possibility of cuing as early as the 1970s.2 Since 1979, researchers have diligently guarded against cuing. For example, Rosh Lewin reported that instructions for Kanzi, a bonobo (pygmy chimpanzee), were “delivered by someone out of his sight,” with other team members wearing earphones so that they “could not hear the instructions and so could not cue Kanzi, even unconsciously."3 More recently, philosopher Stuart Shanker of York University has questioned the emphasis placed on cuing, pointing out that since human communication relies on the ability to understand cues and gestures in a social setting, it is not surprising that apes might rely on similar signals.4
There is considerable evidence that apes have signed to one another spontaneously, without trainers present. Like many of the apes studied, gorillas Koko and Michael have been observed signing to one another.5 At Central Washington University, Loulis, the baby chimpanzee placed in the care of the signing chimpanzee, Washoe, mastered nearly fifty signs in American Sign Language without help from humans. “Interestingly,” wrote researcher Robin
2. Robin Fouts, Next of Kin: What Chimpanzees Taught Me About Who We Are (New York: William Morrow, 1997), 102.
3. Rosh Lewin, "Look Who's Talking Now," New Scientist 130 (1991): 51. 4. Glenn Johnson, "Chimp Talk Debate: Is It Really Language?" The New York Times, June 6, 1995, http://www.santafe.edu/~johnson/articles.chimp.html (accessed February 2, 1998). 5. Frances Patterson and Elton Linden, The Education of Koko (New York: Holt, Rineheart, & Winston, 1981), 51.
Fouts, “Loulis did not pick up any of the seven signs that we [humans] used around him. He learned only from Washoe and [another chimp] Ally."6
The extent to which chimpanzees spontaneously use language may depend on their training. Terrace trained Nim using the behaviorist technique of operant conditioning, so it is not surprising that many of Nim’s signals were cued. Many other researchers have used a conversational approach that parallels the process by which human children acquire...