Tag Archives: Project Nim

Singer Slips Up Over Science of Signs

A guest post today is courtesy of Mark Seidenberg addresses the errors of Peter Singer in his recent piece in the New York Review of Books. Mark was a graduate student at Columbia during the research on Nim Chimpsky, a chimpanzee which scientists attempted to teach sign language to. This piece is the second time we have looked at this issue, after our recent guest post by Herbert Terrace, who was the director of the project at Columbia University. This article has been reposted, with permission from its author, from the Language Log Blog.

Nim Chimpsky and I met when I was a graduate student at Columbia. “Project Nim” is an excellent documentary, a deeply sad story leavened with humor and astonishment at the behavior of the personalities involved . The parts of the movie that cover events I observed—the period when Nim lived at the Delafield Mansion in Riverdale NY and was driven down to Columbia for teaching—was accurate as far as it went. It’s a documentary, not a detailed record of what happened, and it is stronger on Nim’s personal history and the foibles of his human caretakers (and I use the term loosely) than on the science.

I was preparing to write a commentary on the movie and the project, but then Peter Singer’s piece appeared in the New York Review of Books (“The troubled life of Nim Chimpsky“, 8/18/2011). Singer is the Princeton philosopher famous for “Animal Liberation” and other influential, controversial books. His blog post about Nim got many facts wrong and I was moved to write a short response. It might be of interest to Language Log readers.

Full disclosure: I did not work directly on the Nim project or co-author any research papers resulting from the project. I was a graduate student in the psychology department working with Tom Bever (originally a co-PI on the project; he came up with the name); I also was a co-author with Terrace and Bever and another graduate student on a study of rule-learning (!) in pigeons (!!). My first journal article was a critical review of the studies of signing apes by the Gardners and others, co-authored with Laura Petitto (“Signing behavior in apes: A critical review“, Cognition 7(4) 1979).  I’ve contributed to some other articles and book chapters on related topics, such as Laura Petitto and Mark Seidenberg, “On the evidence for linguistic abilities in signing apes“, Brain and Language 8(2) 1979; Mark Seidenberg and Laura Petitto, “Ape Signing: Problems of Method and Interpretation“, Annals of the New York Academy of Sciences, 1981; and Mark Seidenberg and Laura Petitto,  “Communication, Symbolic Communication, and Language“, Journal of Experimental Psychology (General), 116(3) 1987.

Nim Chimpsky’s story is tragic and the “Project Nim” documentary effectively portrays the vanity, foolishness, and gross insensitivity of many of the human participants. Peter Singer is correct that the movie does not provide much information about the science, but his own attempt to fill this gap is ill-informed and incorrect in many details.

On Singer’s telling of the story, the Nim study was superfluous because other research had already settled the major issues. The Hayes’ earnest, laborious and ultimately pathetic attempt to teach a chimpanzee spoken language established the futility of that approach. Their study suggested to many that non-human primates might exhibit their latent linguistic abilities if given an alternative, non-vocal means of expression. This hypothesis was not a frivolous one (even if it turned out to be wrong). Singer approvingly mentions subsequent research by Beatrix and Allen Gardner and their graduate student Roger Fouts; Penny Patterson, longtime companion of Koko the gorilla; Sue Savage-Rumgaugh, and others as establishing the linguistic capacities of apes using gestural signs or keyboards instead of speech. Singer believes that these studies rendered the Nim study unnecessary, and that Terrace “raised the bar” for what counts as language because he found such results too threatening to his own views.

Little of this is consistent with what I observed as a graduate student at Columbia during the Nim project or what I found from close analyses of the ape language studies of the era. The apes in these studies acquired a variety of behaviors. The difficult issues concerned the bases of their behavior, how it did and did not relate to human language, and how one could tell. Singer shows no interest in these essential questions. The positive results that he approvingly cites were the result of applying the most generous possible interpretations to the apes’ behavior. Deciding what Washoe or Koko meant when they signed “banana” was difficult; researchers relied on a discredited method called “rich interpretation”: assume that the ape possesses whatever knowledge a child possesses in using the word. Of course, the basic challenge was to determine whether in fact the ape and child do possess the same knowledge, or how they differed. Other interpretations of the behavior—for example, that it was more like tool use—were not investigated.

Singer is far too receptive to these overgenerous accounts of ape language, which were challenged by people, like me, who had no personal investment in particular outcomes. The Gardners’ research with Washoe also ended when research funding was withdrawn because the science was not credible. Roger Fouts inherited Washoe, maintaining close contact with her and other chimpanzees in his lab, eventually describing his impressions and experiences in a book but conducting no systematic research. When challenged about her fantastical interpretations of Koko’s lugubrious signing, Patterson asserted that, having lived with Koko for many years, only she could properly interpret her language. The Koko “research” was conducted outside the boundaries of organized science: supported by a private foundation rather than research agencies; reported in People magazine but not the peer-reviewed literature. The myth that these animals could talk rests on anecdotes about creative utterances such as the “candy fruit” example that Singer repeats. (Singer conspicuously errs in stating that Washoe learned American Sign Language. She did not. The Gardners used signs loosely adapted from ASL, in English word order.) Examples like “candy fruit” and “water bird” are open to competing interpretations, but, like the filmed snippets of Koko and her kitty or Washoe supposedly teaching sign language to an offspring, they seem convincing to naïve observers, with the assistance of the trainer’s running commentary. Singer is not naïve, and his credulous reliance on this “evidence” is discomfiting.

In short, the bar was indeed raised because the data from these studies were limited and the researchers’ observations and interpretations unreliable, not because the findings were objectionable.

Terrace believed that Nim would genuinely learn to sign because he would conduct a better study. The initial enthusiasm about Nim’s progress arose from this expectation, from the fact that Nim was learning signs rapidly, and from the fact that it would take a few years of data collection and analysis to determine what he was doing. Nim’s teachers (like Laura Petitto) and observers (like myself) communicated to Terrace that the emerging story was not about a breakthrough in animal communication but rather how drastically his behavior differed from children’s. Terrace eventually concluded that the limitation was at the level of combining signs into sentences. In several articles I argued that the limitation was more basic: did any of the “linguistic apes” actually understand that a word (or sign or lexigram) such as “banana” designates a category of objects? That signing “banana” is not merely a way to obtain a banana but is the name for objects with certain properties? The animal could be highly intelligent and communicative and yet still lack knowledge of the concept of “name”, and other foundational elements of language.

This analysis is consistent with and provides a rational account of the behaviors seen in several studies (Gardners, Terrace, Savage-Rumbaugh, Premack), conducted with different species (common chimpanzee, bonobo, gorilla), using a range of methods (signing, keyboards, lexigrams) by researchers holding different assumptions, biases, and expectations.

Nim’s treatment was shameful. The placing of research and personal interests ahead of the well-being of the individual is reminiscent of the nearly contemporaneous study of Genie, the abused, isolated child who was the focus of another poorly-conceived study with a heart-rending outcome. The Nim study did take place, however, and it is important to understand the results that were obtained. They in no way justify his treatment; nor do they justify Singer’s distorted retelling of the events of the era.

Mark S. Seidenberg
Donald O. Hebb Professor
Hilldale Professor
Psychology and Cognitive Neuroscience
University of Wisconsin-Madison

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

http://www.columbia.edu/cu/psychology/primatecognitionlab/