Project Nim – The Untold Story

Cinema’s around the world have been showing “Project Nim“, a documentary about a chimpanzee raised like a human child in the 1970s. However, the documentary misses some key points about the research behind Project Nim, and what was learnt along the way. Herbert S. Terrace was instrumental in this research, directing the project at Columbia University. He has kindly allowed us to reproduce a piece that sets the record straight on the rationale and conclusions of his research.


Project Nim – The Untold Story

During the mid-70’s, I directed a project at Columbia University that tried to teach Nim, an infant chimpanzee, to use American Sign Language (ASL). Project Nim, a documentary currently running nationally, loosely describes the project.

It shows scenes of Nim interacting with his teachers after he was flown to New York from his birthplace at the Primate Institute in Norman, Oklahoma, when he was two weeks old.  Viewers would have to close their eyes not to appreciate Nim’s loveable personality and endearing antics, but they would be hard pressed to see the science on which the project was based.

That’s because the documentary pointedly avoids that topic, which is a shame because the research provided groundbreaking scientific insights into what chimpanzees can tell us about the evolution of language.

The project’s goal was to determine whether a non-human primate could learn the essence of human language: the use of grammatical rules to create particular meanings.  Positive evidence would undermine the then popular claim of continuum between chimp communication and human language. Negative evidence would undermine this claim and require us to ask why chimpanzees are unable to learn a grammatical language.

By the time Nim was almost five, I had collected enough data on his multi-sign combinations to determine the extent of his grammatical knowledge. In September 1977, I ended the project’s research and charted a plane to return Nim to his birthplace.  At five, he would also benefit from being with other chimpanzees because of his size.  If he had continued to live with his teachers, it was likely that one of them would be seriously injured because of his innate aggressiveness, which could manifest itself at the slightest provocation despite his generally benign disposition.

When I returned to New York, I began to analyze the signs that Nim had ostensibly learned during a period of 27 months in which his teachers recorded more than 20,000 multi-sign sequences. While analyzing those sequences I obtained quantitative evidence that Nim could indeed create grammatical sentences and that I had the most powerful evidence to date that a chimpanzee could construct particular meanings by using a grammatical rule.  This would have been exciting news by any standard.

But while preparing my findings for publication, the research took a decidedly different turn. After reviewing a video I’d seen at least a dozen times previously, I noticed that Nim’s positive results were caused by a simple artifact. Nim’s teachers signed what he signed but a quarter of a second earlier. This meant that Nim’s signs were mainly imitative and not spontaneous.  How had other scientists and I missed these prompts while watching the video previously? I realized that when I observed Nim sign producing signs, either in person or on videotape, my attention was always riveted on his hands because I thought they were making history and I didn’t want to miss a second of it. I saw the same symbiotic relationship while viewing other tapes of Nim and movies of other apes (e.g., Washoe and Koko) that had purportedly learned ASL.

This analysis made me wonder why Nim signed at all.  The answer was immediately obvious — to obtain rewards that he couldn’t obtain otherwise. Equally important, I noticed that Nim never signed to start a conversation. He only signed with the expectation of obtaining a reward — e.g., food, candy, drinks and nothing more. Like a child, Nim learned, what I refer to as Language 1. What Nim never learned was Language 2, the ability to converse with someone to convey information that was not about her basic needs, e.g., I just saw Mary or I’m going to the library tomorrow. Language 1 consists of uni-directional imperative statements; Language 2, of bi-directional declarative statements between a speaker and listener. By revealing the true nature of Nim’s signing, the research confirmed the efficacy of unbiased scientific inquiry.

I published my “negative” results, at that time contrarian, in the journal Science and in a book entitled Nim. My conclusions about Nim’s signing have withstood the test of time. But in the film Project Nim, my findings are very briefly described as a failure without explaining why and what failure meant. Apparently the director didn’t understand the difference between negative results and a failure. More important, my results were disparagingly cited as the reason I had returned Nim to Oklahoma, even though I hadn’t discovered the true nature of Nim’s signing until a year after he had been returned to his birthplace.

For me, the omission of the scientific validity of the actual project diminishes the film’s credibility. Also, the director clearly missed an opportunity to educate the public about the science involved in the actual research with Nim. The project proved once again the importance of negative results that they can inspire questions that lead to significant positive results, as was the case with the discovery that space wasn’t filled with ether and that inanimate matter did not give rise to animate matter.

A few years after I had returned Nim to the Primate Institute, it went bankrupt and he was sold for medical research. But thanks to Nim’s signing ability, I was able, with the pro bono assistance of a lawyer, Henry Herrmann, and Bob Ingersoll, a graduate student, to rescue him and place him in an animal sanctuary run by philanthropist Cleveland Amory.  Nim lived there with a mate named Sally and three playmates, Midge, Kitty and LuLu, until he died from a heart attack at age 27.

In the end, Nim’s inability to learn a language deepened our understanding of the basic difference between the minds of humans and apes. Most important, apes lack a “theory of mind”, the ability to perceive what another ape is thinking. Without that ability, it is impossible for their signing to rise above the level of begging to conversation, the essence of human language.

As charming as Nim was, he was not human and to anthropomorphize him as such is not only bad science but also dangerous sociology, e.g., chimpanzees are fully capable of maiming and killing humans.  Nim himself hurt several people as he matured.  Nonetheless, he was clearly special. He was a remarkable creature from the living tree of evolution, as are his threatened relatives, and he should be greatly respected for sharing himself and his abilities in the pursuit of what it means to be human.

Herbert S. Terrace
Professor of Psychology & Psychiatry
Columbia University

14 thoughts on “Project Nim – The Untold Story

  1. This post was about the notion that apes can talk. They can’t. Period. Hollywood would want to think otherwise.

    You brought up theory of mind in your comments. Here, a critical view of the literature clearly shows chimps have limitations even when compared to children:

    Click to access darwins_mistake.pdf

    See also:

    As for protection to animals — I am all for animals having legal protection. I am against basing such protections on Hollywood science.

  2. You seem determined to make a suggested clarification into a major confrontation. I said nothing about about “personhood,” which is a slippery trendy term that contributes nothing to a discussion unless it is precisely defined. As to “legal rights,” depends on how you define that too. Pet animals in much of American are protected BY LAW from abuse. That doesn’t seem “meaningless” to me.
    If you look above, you’ll see that I wrote about PROTECTION for chimps – even though they can’t be “full moral agents” – which is the status of children when they are children. If you insist on using the endpoint of ontogeny as your touchstone for “rights,” you open difficult questions about the mentally disabled.
    If we go around again, please reply to what I’ve written and drop the “seems to me” routine.

  3. Human children are in a developmental path to become full moral agents. Chimps are not.

    We do not hold children responsible for their actions in the same way we hold adults responsible (e.g., we do not have a death penalty for a minor committing a murder) nor do they have the same rights (children cannot vote, drive or drink).

    Yes, apes are worth of moral consideration and humans must care for them. However, it seems to me you are arguing for endowing them with personhood and legal rights which, in my view, is meaningless.

  4. Darioringach makes an important point, but its implications are limited, i.e. chimpanzees cannot be treated as citizens and to do so in any way is anthropomorphic. However, we do protect non-citizens who lack adult moral responsibility from abuse: young human children. Given the increasing number of equivalences that have been established between apes and human children, it seems reasonable that the two groups be afforded the same protections.

  5. Aside from the scientific discussion if chimps can talk (no they can’t) or if they have theory of mind or not (debatable), one could simply ask if they are able to behave as full moral agents within our community — respecting the interest of others and assuming responsibilities for their own actions. I think we all agree this is not the case. And yet, much of Hollywood portrayal of animals seems to suggest the opposite.

  6. The last comment by Jennifer is very important. It dispels the vague and simplistic idea that “theory of mind” is monolithic. Addressing its components will be more scientifically profitable. An analogy can probably be drawn with the Piagetian view of cognitive development.

  7. SoR: The failure of people to realize “that you cannot socialise a chimp” [or an orca or an African elephant] has nothing to do with the presence or absence of a theory of mind in the animal. It arises from ignorance and/or foolishness in the human mind. If a religious fanatic kills you because you have despoiled one of his symbols, this doesn’t tell you that he has no theory of mind.

  8. Chimps to date have demonstrated difficulty with the ‘false-belief’ task (understanding if another individual is misinformed), but they do very well with understanding if an individual is ‘ignorant’ or ‘informed’. Just because they so far have not demonstrated the third level of ‘misinformed’ doesn’t mean that they don’t understand that others have perceptions and intentions that may differ from their own. As Bloom & German (2000) stated, the false belief task “taps one aspect of people’s understanding of the minds of others. Nothing more, nothing less.”

  9. Glenn – On the subject of anthropomorphising chimps, I think the point was that people have died because they have not appreciated that you cannot socialise a chimp – they are wild animals:

    Jennifer – Call and Tomasello (who worked with Hare) considered apes to have Theory of Mind only when such a term was broadly interpreted. Apes difficulties with understanding false beliefs suggested that apes do not have a theory of mind in the stricter sense.

  10. Dr. Terrace missed the point of the movie entirely. This wasn’t about the science. It was about how Nim’s life was disrupted and frankly destroyed by science. Whether it was language research or hepatitis research, the very fact of Nim’s birth and existence doomed him to a life of misery and suffering. It’s a unique kind of suffering to be caught between two worlds, to grow up thinking you are human and living a life of comfort and suddenly having it all taken away. But it is suffering nonetheless, just as chimps used exclusively in biomedical research (who are given no illusions that they are anything but creatures whose lives are worthless in the eyes of those who would torture them) suffer. My heart broke for Nim. I don’t care if Nim could or could not use language. I care that his life was torn apart by human arrogance.

    But as far as the science goes, it is laughable to believe that apes do not have a ‘theory of mind.’ (Sidebar–theory of mind is not the ‘ability to perceive what another ape is thinking.’ That’s called being psychic, and I am certainly a skeptic that anyone has that ability! Theory of mind is essentially being conscious of the fact that you have a mind, and that others have minds too–and because of that you are able to discern the perception or point of view of others, and make logical conclusions about another individual’s intentions or expected behavior.) Dr. Terrace is behind the times. Dr. Brian Hare and others have demonstrated through elegant cognitive and behavioral studies that apes in fact do have a theory of mind. Anyone who works with and cares for apes knows it to be true also, not through experiments but through our day to day interactions with them. I don’t need an experiment to demonstrate that humans have a theory of mind. Likewise, I don’t need experiments to prove to me that chimps (or other apes, or other species) have theory of mind. I have life experience that has proven that just fine.

  11. The method was flawed ergo you cant make any conclusions from it at all, either negative or positive, what kind of scientist are you?

  12. Since this piece purports to “set the record straight,” it should be noted that a number of researchers have published evidence indicating that chimps and other apes do have a theory of mind. One self-assured declaration does not prove the negative.

  13. “As charming as Nim was, he was not human and to anthropomorphize him as such is not only bad science but also dangerous sociology, e.g., chimpanzees are fully capable of maiming and killing humans.” This is a rather strange sentence. Recognizing that chimps can maim and kill humans is not the opposite of anthropomorphizing. Humans maim and kill humans all the time.

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