The most important sign language study done with an ape was surely the first one back in the 1960s, with Washoe, for it established that chimpanzees can use American Sign Language (ASL).
The most decisive such study, however, was probably the one a decade later, with Nim Chimsky because it put a halt to such inquiries.
Herbert Terrace, the lead investigator, announced he had changed his mind (always an eye-catching action). Terrace began the project expecting to see that a chimpanzee could master sign language. At first, the data had seemed to support that hypothesis. However, upon closer examination Terrace realized that Nim did not engage in much spontaneous expression. Nim’s use of signs was a way of controlling his human attendants. He was not sharing information or conversing.
Now a documentary film, Project Nim, has come along to leave me with a sense that the Nim project was a scientific scandal. No conclusions, one way or the other, should be based on it, except for the indisputable fact that Nim did learn to make a number of signs and would sometimes string them together.
The film is based on a book, Nim Chimpsky: The Chimp Who Would Be Human by Elizabeth Hess. The documentary was directed by James Marsh, a fine filmmaker whose earlier movie¸ Man on a Wire, proved that documentaries could be suspenseful, even when you go in knowing the outcome. Nim’s story gets the full professional treatment in a movie that looks very good and moves the emotions too. There are some drawbacks as well. Nobody ever mentions that Nim’s name is a play on Noam Chomsky. When I first learned of the project, back in the 70s, I laughed mightily at the name, although now that I’ve seen the movie I’m a bit ashamed of myself. The name is a joke because Terrace never took Nim’s individuality seriously.
The movie makes it clear that Nim had a nightmare life — the side that I expect most reviewers to discuss—but it also indicates that the project was an absurd mess. Shortly after his birth in November, 1973, Nim was taken from his mother and placed in the arms of Stephanie LaFarge, a former student of Terrace’s, who was experienced with children and had agreed to raise Nim as a member of the family. Terrace was overseeing the project, but not as a constant part of Nim’s life. His focus was on language; would Nim learn sign language?
Scandal #1: nobody in LaFarge’s household was fluent in signing. In a normal, human household, infants are surrounded by fully competent language users. Nim was not among fluent signers and they did not sign between themselves. There was no hope that Nim would just pick up signing the way babies pick up a language. From the start, therefore, he would have environmental disadvantages not found in the normal family.
Scandal #2: Terrace had no clear program for introducing Nim to sign language. LaFarge was smart enough to try shaping Nim’s hands to get him started signing. From there the vocabulary grew. I got the impression that as the project went along, Terrace started to worry that he was producing one long anecdote. He brought in a second researcher, Laura-Ann Petitto, who tried to put more order into the material. Nim was taken from LaFarge’s home (which turns out to have been about two blocks from my apartment on Manhattan’s Upper West Side) and moved into a large estate in Riverdale, the Bronx. A couple of other sign-language teachers were also introduced, but by then the situation had gotten out of hand.
Scandal #3: There seemed to be no new hypothesis behind the study. I have to be careful, basing commentary on a movie, but we get no clue that Terrace was looking for something new. Neither LaFarge nor Petitto give any hint of checking something out more than some this-vs-that search. By the time of the Nim study, Washoe (b. 1965) had already learned ASL. Also Lucy Templin (b. 1964) was being raised in a human home and was learning some ASL. Koko (a gorilla, b. 1971) was already learning ASL. So what was the point of the Nim study, beyond doing something fashionable?
Scandal #4: There was no definition of language strong enough to distinguish between gesture and signs. By the time the Nim project began Jane Goodall already knew that chimpanzees in the wild make gestures. Terrace was probably going on the Chomskyan definition of language being the ability to produce grammatical sentences. But that definition doesn’t help distinguish a gesture from a word, especially when words come in the form of hand signs. Several of the most common "signs" in the documentary—signals asking for a hug or to play—are the sorts of gestures that are frequent in the wild, requests for something. Terrence’s realization that Nim was not really using language seems to have come when he recognized that Nim was gesturing rather than verbalizing. It was an important insight, but the philosophers Charles Sanders Pierce and Ernst Cassirer had already worked out the basic differences between signs and symbols. A well designed study would have been alert to the issue from the beginning.
No, I am not arguing for a better designed Nim project that would settle the issue. By now the issue is settled. More focused research by scholars like Simone Pika and Michael Tomasello has shown that chimpanzees are smart enough to recognize the meanings of some signs, but they are not cooperative enough to use language. That principle forms the basic thinking of contemporary research into language origins: when the human lineage became cooperative it already had the intellect to use words at the level of a two-year-old. That was enough to get our ancestors started talking; from then on they went down a new path.
About the Author: Edmund Blair Bolles is a science writer who maintains a blog, Babel's Dawn, on the origins of speech. His sixteenth book, Babel's Dawn: A Natural History of the Origins of Speech will be published by Counterpoint this September. He can be reached on Twitter @ebbolles.
The views expressed are those of the author and are not necessarily those of Scientific American.
Related at Scientific American: The Sundance Diaries: The Interrupters and Project Nim.