Early Career and the Mechanics of Teaching Apes Sign Language
Dr. Herbert Terrace, eminent psychologist and professor at Columbia University received his PhD from Harvard University in 1961. Before he was interested in psychology, however, language was his primary interest. "Undergraduate literature courses and language had always been my main interest, and I discovered that the key to understanding them is in psychology, which brought me to studying the evolution of language,” says Dr. Terrace.
Renowned for his studies on language with the ape Nim Chimpsky, Dr. Terrace describes the mechanics of teaching American Sign Language (ASL) to an ape as being relatively simple. "Apes are not the least bit interested in signing, but they do want to be your friend. Because of this, they will go along with the motion when you mold their hand to make a sign but with the expectation that they will receive a reward: they imitate only as a step toward getting what they want.”
The process goes something like this, "You tell a chimp, ‘if you want a banana, show me the banana sign,’ and you teach him how to make the sign for banana; when he does this, you give him a banana,” explains Dr. Terrace. "As time goes by, he realizes that he does not get a banana unless he makes the sign for it. Effectively, it is tantamount to going to a vending machine and pressing the button for ‘banana.’ There is no difference between that and teaching an ape sign language.” According to Dr. Terrace, Nim did not learn language at all, but simply a trick to be rewarded, a result quite different from what he hoped to find.
Honestly Reporting Results
Dr. Terrace’s study with Nim Chimpsky is a textbook example of how negative results can still lead to interesting conclusions. As he puts it, "the only line between success and failure for scientists is whether or not they honestly report their results.”
"I had initially read my results as being very positive that a chimp could learn the rudiments for grammar in ASL: this conclusion was soon to be accepted by the scientific community. However, after reviewing the tapes from a different perspective, I realized the results were not as I had first assumed. In the beginning, I kept my eyes only on Nim; I thought that history was being made. Later, I widened my view to see the entire picture. When I did this, I saw that the teacher was unconsciously indicating what signs Nim should be making, and I realized that most of what Nim was signing was being cued by the teacher. Once I discovered that, it radically changed my conclusion: Nim, and therefore apes, could not learn language in the same manner that we can,” according to Dr. Terrace.
"Had I reported the results based on my original assumptions, the true conclusion may not have been discovered for years. Some researchers in a century from now might say, ‘No, Terrace’s results do not work because the study is not replicable.’ I could have been dishonest and let the study go on to be published with my original conclusion, but I knew that I could not let that happen. Although the study had a negative result, it was a very interesting negative result.” Dr. Terrace’s experience in dealing with this negative result is important for students to understand: negative results do not always equal failure.
Human Versus Ape Communication
"Chimps communicate through what I call begging.” Dr. Terrace goes on to say, "They are learning what tricks they have to perform in order to get a reward and this can be very subtle at times. In several projects, I have seen the teacher walking around with a pocket full of candy; as long as the candy is swept to the chimp every so often, he or she will continue playing the game. Humans are different from chimps in that they can have a conversation and understand one another; chimps simply demand without caring who satisfies that demand. My argument is that you cannot have a conversation unless you have a theory of mind; it is the key to the notion of acquiring any language,” he says” A theory of mind is the ability to understand what people know, think, or feel in relation to oneself. "I think the way humans have a theory of mind has to do with a lot of anatomical twists and turns that were never motivated by language; the stars just happened to be in the right position and human infants for a few hundred thousand years were born with the capability of forming a theory of mind,” Dr. Terrace explains. "What chimps have convinced me of is that problem solving on the individual level is not enough to learn language. What is needed is social intelligence, because language is different from the automatic responses we are born with. Since I happen to believe a theory of mind is necessary to learn language, I do not see how any of the apes are going to qualify,” he says.
Presently, Dr. Terrace is studying how nonhuman primates learn to produce sequences without words. "I want to know how they organize what they have to remember in a way that facilitates that remembering,” he says. "What I decided to do after the Nim project was to create a new paradigm where all the choices are laid out for the ape. It is sort of like going to an ATM: you put in your pin and touch each item in the correct order. For my monkeys, I do not want them to rely on muscle memory: I want to make sure they learn cognitively as opposed to just motor responses. For each trial, I reconfigure all the items so the apes have to think about it cognitively. I want to make sure there is nothing in the external world that can give them any clue as to what to do next.”
For students interested in thought processes and the evolution of language, the field of primate cognition is as alive and captivating as ever, and Dr. Terrace’s research is important for students to investigate to gain his perspective concerning apes and language. One of Dr. Terrace’s most important contributions to the field of primate cognition is his example that a negative result can lead to many interesting conclusions.