Can Apes Really Speak?

by Scott Jann

University of Minnesota
Linguistics 3001
July 16, 1996

In an episode of Star Trek: The Next Generation, Lt. Commander Data, who in the show was an android, was questioned of being sentient. Was he actually sentient? It is very hard to tell. Of course, if you just ask him, he’d say that indeed he was. How can you distinguish an actual sentient response from the possibility that he was programmed well enough to answer all the questions as well as an actual sentient being.

This is very similar to the problem that researchers face when they have taught non-human primates (chimpanzees and gorillas) human language. They don’t have the same vocal tract as humans and are not able to produce the same articulated sounds as humans. Researchers have used primarily American Sign Language as an alternate means of communication. The problem with this is similar to the one suggested before: what are the chimpanzees actually doing? Are they imitating the human researchers that taught them the signs? Are they responding to cues from the researcher? Are they, in fact, able to speak sign language the same as a human?

Assuming that the chimpanzees are merely imitating the researcher is a reasonable assumption, however, this doesn’t seem to be the case at all. The primates have been taught, for instance, the word for apple1. You’d then assume that since the researcher made a certain sign while referring to a whole apple, the subject would only make the same sign in the same circumstances. Beyond recognizing the apple, the chimpanzee would also recognize a sliced apple as an “apple”. This is evidence that there is more than imitation happening.

Furthermore, it has been suggested that the primates are merely being cued by the researcher. One might think that the researcher either consciously or unconsciously is somehow indicating to the subject signs which it should make. It is possible this happened in some of the cases, but there have been others which the researcher has been aware of this problem, and used double blind2 tests to ensure that no hidden interaction could be taking place. I believe that at least in these cases, if not all, cuing hasn’t been taking place.

If both of these previous items are true, then it could seem as if a chimpanzee is actually using sign language the same as a human. In fact, some of the researchers in this field compare the signing ability of the primates as about the same as a two year old human child. However, one unique feature of human speakers is that they often make utterances that have never been uttered before. The closest observation to this in a non-human primate so far was with a chimpanzee named Washoe3 who signed “water bird” after seeing a duck for the first time. Washoe was a young chimpanzee who was taught sign language by Allen and Beatrice Gardner, in an experiment. It is very reasonable to think either Washoe was being creative, since she had never saw a sign for a duck. It is also possible that Washoe was, being in the presence of a lake (water) and seeing a creature with wings upon it (a bird), stating that there was both “water” and a “bird”. Secondly, humans make observations about their environment, and make abstract statements or talk of their emotions (i.e. “The sun is bright.” or “I’m happy.”)4. In addition, humans tend to be curious, and ask a lot of questions beginning with “why”. Chimpanzees have been observed to do almost none of these.

I believe that this research has shown us a window into how chimpanzees think. Unlike humans, they tend to only understand concrete phrases. Also they are not as creative as humans, as far as their ability to create novel utterances. Linguistically, I would say chimpanzees are able to learn human language only as far as they are able to understand it, which is a relatively limited way compared to humans. They can only communicate concrete phrases, beyond that they are quite lacking, whereas most of human language involves such abstract ideas.