Science Literature

Starting in 1973, Herbert Terrace led an ambitious project to examine the capability of chimps to develop sign language. The chimp participant was born at the Institute for Primate Studies in Oklahoma and was taken from his mother after about a week and handed to Stephanie LaFarge who acted as a surrogate parent. The chimp was effectively adopted. In a recent piece in Nature, Terrace explains why he initiated the project:

"After serving as a graduate assistant at Harvard University with behavioural psychologist B. F. Skinner, I heard that Allen and Beatrix Gardner at the University of Nevada, Reno, were teaching sign language to a chimpanzee named Washoe. But when I looked at their data, I wasn't sure that the chimp's sequences of hand signs were grammatical. I decided to do a study to collect everything a chimp signed, and document the circumstances. We wanted to have full records of the discourse between the infant chimp and the caretaker."

Nim Chimpsky (source here)

The experiment design was based on some important theoretical considerations about the development of language. Influenced by his background in behavioural psychology, Terrace set out to challenge the ideas of the linguist Noam Chomsky - in particular his claim that grammatical speech is uniquely human. Behaviourists tend to the view that animals can be taught to do almost anything, and the Los Angeles Times report says that the "Skinner-Chomsky rivalry framed the Nim project". The new name for Chimp No 37 was Nim Chimpsky, sufficiently distinctive to draw my attention to the project during the 1970s.

To cut a long and fascinating story short, the project ended up supporting the theoretical perspective of Chomsky and underlined the differences between chimp communication and human language. The most influential paper emerging from the project team was published in Science in 1979, with the title: "Can an ape create a sentence?" The answer was no - at every level. Long utterances were not semantic or syntactic elaborations of short utterances - this is quite different from the communications of human children. As the length of utterances of children increase, so also does the complexity of those utterances. This increase in complexity was not observed with Nim. The researchers concluded that all the evidences accumulated in support of apes creating sentences could be explained by reference to simpler non-linguistic processes. They found that animals can learn symbols and signs, but do not show any capability to master the conversational, semantic, or syntactic organisation of language. In answer to the question "Did the experiment meet your expectations?" Terrace replied:

"The language didn't materialize. A human baby starts out mostly imitating, then begins to string words together. Nim didn't learn. His three-sign combinations - such as 'eat me eat' or 'play me Nim' - were redundant. He imitated signs to get rewards. I published the negative results in 1979 in the journal Science, which had a chilling effect on the field."

An interesting follow-up question is: "Why couldn't Nim put a sentence together?" This is particularly important to Darwinists and many other evolutionary thinkers, who go along with Darwin's claim, in The Descent of Man, that there is "no fundamental difference between man and the higher mammals in their mental faculties". Terrace's answer points us to a major difference between humans and animals: only humans have a theory of mind.

"I haven't seen any evidence that a chimp has a theory of mind. It can predict behaviour, but the concept of another individual's thinking is foreign to it. So it is pointless for a chimp to start a conversation: why talk unless you expect a reply?"

After the project, Terrace returned Nim initially to the Institute for Primate Studies. However, after they ran out of funding, he did not want Nim sold as an animal for medical research. Terrace found him a home in a giant cage at a ranch for celebrity animals in Texas where he lived until the year 2000 when he died of a heart attack. But the story does not end there. There are many people who still think of Nim as an adopted human, a chimp who thought he was a boy, an animal that acquired language skills. One of them is Elizabeth Hess, who published a book in 2008 to tell a different story:

"He [Terrace]concluded that Nim and the other chimps who appeared to be communicating were merely mimicking, making fools of the scientists chatting with them. In effect, Terrace had written an obituary for ape-language research. After years of crowing about his achievements with Nim, he leapt into bed with his adversaries and battered other practitioners.
His opponents argued that his failure had been his own. He had been unable to handle his own chimp or provide Nim with consistent teachers. Worst of all, he had ended the study too early to get significant results; at the very least, Terrace's about-face was premature. Then there was the inconvenient fact that once Nim had learnt to sign, he often initiated conversation with humans. Didn't that count?"

The book is now a film. It would appear that the book's agenda resurfaces in the film. Although the science issues are not prominent, viewers are given an emotional roller-coaster as they follow the life of Nim Chimpsky - who is presented as having a theory of mind. Terrace is not happy:

"I'm upset because the film creates the impression the project was a failure because it didn't turn out the way I'd hoped it would when I started," Terrace declared recently in his office at Columbia, where he still runs the Primate Cognition Laboratory. "The only line between success and failure for scientists is really whether they honestly report their results, and I did that."
But that's not all Terrace is displeased about. "The film also suggests I was not affectionately involved with Nim. And that's not true." Marsh, he added, has "made a technically good film, but he's misrepresented me, and he misrepresented the science."

One thing that impresses me about the 1979 paper is the thoroughness with which the data is reported and discussed. The writers are people who started out to challenge Chomsky's theoretical approach, but ended up falsifying their own hypothesis. This is the way science is supposed to work. They impacted the whole field of ape-language studies - but there are other agendas operating. There are people who "know" that there can't be a discontinuity between apes and humans, because that is inconsistent with their understanding of evolutionary theory. So they find ways of undermining the research and promoting their own views. This is ultimately the same problem that we face elsewhere with evolutionary theorists - people confuse theory with fact and see overwhelming evidence where there is plenty of scope for divergent interpretations of the data. Will we ever learn?

Q&A: The interpreter
Jascha Hoffman
Nature, 475, 173 (14 July 2011) | doi:10.1038/475173a

In 1973, Herbert Terrace, a psychologist at Columbia University in New York, embarked on an experiment to teach sign language to an infant chimpanzee named Nim Chimpsky, after linguist Noam Chomsky. On the release of the documentary Project Nim, Terrace talks about research ethics, chimp cognition and the origins of language.

Can an ape create a sentence?
H.S. Terrace, L.A. Petitto, R.J. Sanders and T.G. Bever
Science, 23 November 1979, 206, 891-902 | DOI: 10.1126/science.504995

Abstract: More than 19,000 multisign utterances of an infant chimpanzee (Nim) were analyzed for syntactic and semantic regularities. Lexical regularities were observed in the case of two-sign combinations: particular signs (for example, more) tended to occur in a particular position. These regularities could not be attributed to memorization or to position habits, suggesting that they were structurally constrained. That conclusion, however, was invalidated by videotape analyses, which showed that most of Nim's utterances were prompted by his teacher's prior utterance, and that Nim interrupted his teachers to a much larger extent than a child interrupts an adult's speech. Signed utterances of other apes (as shown on films) revealed similar non-human patterns of discourse.

See also:

Tyler, D. Was Darwin's thinking about continuity of mind well grounded? (ARN Literature blog, 17 April 2009).