Can a chimpanzee make a statement?

Abstract

The field of ape language has been in turmoil since the publication of Terrace's (1979) work with. Nim, a chimpanzee. Terrace's findings regarding the linguistic competencies of apes contrasted sharply with those put forth earlier by Gardner and Gardner (1971). We discuss these and other ape-language projects and contrast the preverbal communicative skills of chimpanzees with those of human children in order to, determine the cognitive competencies that chimpanzees bring to the task of language acquisition. We conclude that children enter the one-word stage with a gestural-referential complex of abilities that permits them to engage quickly in a process of mutual vocal reference and that predisposes them to view words as behaviors that stand for or replace objects. Chimpanzees do not seem to develop spontaneously a similar gestural-referential complex of communicative skills, and therefore they do not readily comprehend the act of reference that the teacher is engaged in while pointing to and naming objects. Thus, although chimpanzees imitate the symbol, they do not readily interpret the symbol as a referent in the manner that a human child does. This distinction between child and chimpanzee has not been made previously, and it is suggested that the lack of such a distinction has resulted in overinterpretations of apes' linguistic abilities. Data are presented that demonstrate that the gestural-referential complex can be developed, with training, in the chimpanzee and that, consequently, naming with reference does appear. This is demonstrated in controlled tests with two chimpanzees. A review of the training that preceded the emergence of referential function in these chimpanzees suggests that symbolization is not a unitary skill but rather a combination of diverse productive and receptive skills. This view is supported by human data. Contrasting Views of Indication in Apesdifference between the use of language by apes ", , _ , , and children lies in the fact that apes do not Terrace and Rumbaugh seem motivated to use their words in any sort Terrace, Pettito, Sanders, and Bever (1979) of declarative or indicative sense. That is, they have asserted that a profound and important do not typically use symbols to announce to others what they are about to do or to draw the attention of others to objects or events.

Spontaneous symbol acquisition and communicative use by pygmy chimpanzees (Pan paniscus).

“…It has also been shown that when a chimpanzee is systematically taught the communicative skills of requesting, labeling, and comprehending, indicative referential symbol usage can then appear without further training (Savage- Rumbaugh, 1984bRumbaugh, , 1986Savage-Rumbaugh, Pate, Lawson, Smith, & Rosenbaum, 1983). With the appearance of indicative usage, apes go beyond conditioned request-oriented utterances and become able to make statements about behaviors they are going to engage in, in advance of actually emitting those behaviors.…”

“…With the appearance of indicative usage, apes go beyond conditioned request-oriented utterances and become able to make statements about behaviors they are going to engage in, in advance of actually emitting those behaviors. The ability to use symbols to orient the attention of others to particular aspects of the environment, other than the fulfillment of immediate needs, also appears to accompany the onset of indicative communication (Savage-Rumbaugh, 1984b, 1986Savage-Rumbaugh et al, 1983).…”

“…However, Loulis has not been tested to determine whether he in fact understands the referents of any of these gestures. Because it is well documented that both captive and wild chimpanzee populations learn various nonreferential gestural signals (McGrew & Turin, 1978), it may be that Loulis' gestural capacities do not function any differently from those of other captive apes who use simple nonreferential gestures (Savage-Rumbaugh, 1984a, 1986Savage-Rumbaugh et al, 1983;van Lawick-Goodall, 1968). In any case, until Loulis's abilities are appropriately assessed, we cannot conclude that he has learned referential signs.…”

Editorial Commentary

“…It is equally clear that all vertebrates are capable of forming formally similar associations, and it is not clear that such association-formation is all that occurs when a human learns the meaning of a word. Savage- Rumbaugh et al (1983) have brought similar arguments to bear on the results reported by, among others, Gardner and Gardner (e.g., 1978), Premack (1976), and Terrace et al (1979) but the effort by Savage- Rumbaugh et al (1983) to demonstrate "representational" as opposed to "associative" naming has itself been questioned (e.g., Ristau 1983;Sugarman 1983).…”

“…In conclusion, I find it implausible to assume that only humans can acquire language in the face of suggestive work to the contrary with chimps and especially the ongoing unpublished dolphin work of Herman and his colleagues (Savage- Rumbaugh et al 1983). The possiblity of a continuum of linguistic skills remains strong.…”