After years of pigeons and rats, Herbert S. Terrace, a professor of psychology at Columbia University, thought he might like to work with a chimpanzee. What would happen if you raised a chimp as a member of a human family, socialized it so that it was just as concerned about praise and status as it was about food, and provided it with a hothouse learning environment. Then could we at last answer the question, can apes learn language?
The language would have to be a visual one to compensate for an ape's inability to articulate enough human sounds. But one ape had already proven itself able to master many words of American Sign Language, the language of the deaf, and a chimp named Sarah had learned an artifical language using plastic chips of different colors and shapes. Another, called Lana, had learned to communicate in Yerkish, an artificial language programmed by computer. But in those studies the animals had been kept in a cage. What would happen if Nim Chimpsky as Terrace called his baby chimp, was treated like a human infant?
In this book, with its fascinating photographs, we see how, installed in a Manhattan brownstone with a foster "family," Nim developed normally: bottles and burping, diapers and crying -- "far louder and more piercing than anything one might hear from a child." And in between, there were patient and dedicated teachers "signing" to Nim, molding his fingers into the proper shapes, recording his every gesture. He mastered his first words drink, up, and sweet, at four months, and had been signing in baby talk weeks before that. After 44 months, he had mastered 125 words, and used combinations of two, three and more signs.
As he got older, Nim's lessons became more formal. "When he was brought into the classroom, he was expected to hang up his hat, sweater, and coat on a hook . . . At breakfast, as well as at other meals, Nim was expected to sit in a high chair, to eat with a spoon, and to wipe both his face and his high chair when finished . . . After breakfast, the teacher would show him various picture books, toys and other objects in order to see what interested him" for the daily lesson. Nim also tried to include himself in cooking, cleaning, washing clothes and cars, a repearing things. He always appreciated an opportunity to help out and was better-behaved when he was allowed to help.
The experiment was beset with endless personnel crises -- Nim had 60 teachers and 40 volunteers helped to analyze the data -- and was a cliffhanger financially, careening from grant to grant. Terrace was "faced with the need to provide Nim with caretakers he liked, sixteen hours a day, seven days a week." There was much "competition over who was the most effective teacher, who loved Nim the most, and whom he liked the best." This bred the "Sturm and Drang of five months of debate," and the "sessions began to sound like emotionally charged PTA meetings."
Terrace concedes that this "emotional turmoil" may have interfered with Nim's learning and exacerbated the natural, playful destructiveness of an immensely strong juvenile chimpanzee. "The slightest noise caused Nim to hoot and leap into the arms of his teacher. At times he was so scared he tried to hide under his teacher's skirt." Special doors and locks couldn't contain him and he "occasionally had us chasing him through the halls and stairwells." The acrobatic antics and temper tantrums of a pongid Dennis the Menace took its toll on his teachers, too. "It proved impossible to prepare new teachers fully for the quickness and ferocity of his outbursts of aggression." A teacher who failed instantly to "dominate" Nim through eye contact would end up with a scratch, a bite and torn clothes. Terrace confesses that Nim was at times "an unmanageable brat." And he admits, "I worried about the way he sank his teeth into the base of my neck."
About half the book (as well as a recent Science magazine article) describes methodology, analysis and conclusions. Terrace believed his record of Nim's progress provides "a more detailed corpus of utterances than had been obtained from any other chimpanzee and, so far as I know, from any child," and that his year of statistical and semantic analysis "represents the most intense and systematic effort ever made to evaluate a chimpanzee's ability to create a sentence."
Terrace believes that while Nim was successful in communicating to satisfy his wants, his combinations (like those of other apes) tended to repeat what his teachers had just signed. Other combinations could just as plausibly be interpreted as random or simply learned by rote. Terrace believes it is "premature" to conclude that a chimpanzee's sign-combinations indicate the intellectual capacity to arrange words grammatically, or with the same structure as the sentences of a child. Other experimenters have now been interviewed as saying, "Maybe Terrace got a dumb chimp," or that funding problems and continually changing staff interfered with learning. The debate continues.
After almost four years, Terrace returned Nim to his birthplace in Oklahoma. "He began to scream and tried to force the door open . . . I will never forget Nim's incessant, ear-piercing screams, and his look of fear and anger when I abandoned him in his cage." Later there was a brief reunion, along with evidence that Nim had adapted to his new environment.
Terrace has two conclusions that are worth consideration by others who might be tempted to repeat the experiment. First: "The success of this type of research may, more commonly than is recognized, depend on the efforts of a single individual whose effectiveness is hard to predict from prior experience." And "if one's aim is to be a father to a chimpanzee, one should be a rich father with as small, stable, and professional an extended family as possible."