In response to:
Apes R Not Us from the May 30, 1991 issue
To the Editors:
I am sympathetic with Lord Zuckerman’s astute discussion of the question, “Can apes talk?” [NYR, May 30] and agree with his conclusion that “apes cannot be trained to use or understand any syntactic rules.”1 I would, however, like to address a question that he did not confront, “Was the emergence of language ordered by grammar and syntactic rules coincident with the emergence of Homo erectus?”
Before speculating about the origins of grammar, it is prudent to ponder the origins of the referential use of individual words.2 Unlike apes, children use individual words to comment about objects for the sheer joy of communicating. Adults do not reward a child with a tree when she points to one and then says tree, or with an elephant when she identifies one in a picture book.3 By contrast, there is no evidence that apes communicate about things. As Lord Zuckerman observes, apes use language not as “…a way of conversing, but a game associated with pleasurable reward.”
Although the origins of human language are unclear, one contributing factor must be the adaptive value of communicating meanings that cannot be expressed in a single word (e.g., the large tree or the single-tusked elephant ate the large tree). It appears, therefore, that the cognitive leap to language occurred in two stages: first, developing the lexical competence to use arbitrary symbols to refer to particular objects and events, and then the syntactic competence to combine and inflect those symbols systematically so as to create new meanings. Because of Chomsky’s compelling and influential arguments that language presupposes syntactical competence, investigators of ape language (myself included) overlooked the uniquely referential function of individual words. That function should be included in speculations about the evolution of language.
Lord Zuckerman’s skepticism about anecdotal evidence that has been used to support claims of analogs of other human functions by monkeys and apes is well taken. There are, however, effective methods other than the anecdotal one that have been used to study animal behavior. In particular, much progress has been made in recent years by laboratory studies of animal cognition.4 ,5 These studies refute the Cartesian dogma that thinking presupposes language, a dogma which flies in the face of evolutionary theory and much empirical evidence. Curiously, it also denies the possibility of thought in preverbal infants. It is admittedly difficult to investigate how animals and human infants think without language but there are ample rewards for doing so. At the very least it is consistent with the sound scientific principle of simplifying one’s subject matter. Instead of trying to investigate complex cognitive processes in adult human subjects, which presuppose language, many investigators have asked (with considerable success) the simpler question of how language adds to demonstrable cognitive abilities of animals.
Professor of Psychology
New York City
To the Editors:
It is gratifying to read Lord Zuckerman’s generous assessment of my new book, Uniquely Human: The Evolution of Speech, Thought, and Selfless Behavior. However, some apparent misunderstandings are present in the review concerning my position on genetic variation and the acquisition of a child’s first language. The review also obscures the principal distinction between my views and those of Derek Bickerton concerning the neural bases and evolution of human syntactic ability.
As Lord Zuckerman notes, a genetically determined capacity for syntax (the Chomskian “Universal Grammar”) would have to account for the fact that virtually all children (excluding severely retarded individuals) acquire language in widely disparate environments. However, Lord Zuckerman misstates the nature of my objection to Universal Grammar—which is to biologically implausible formulations that do not take account of genetic variability. Until the past year, virtually all theoretical linguists working in the Chomskian tradition claimed that the Universal Grammar was identical in all humans. The algorithms that they devise to specify Universal Grammar take this supposed identity as a given, and consist of sequences of tightly nested rules and principles which must all be in place if a child is to acquire language. The “dislike of the concept of a genetically determined ‘universal grammar”‘ which Lord Zuckerman attributes to me concerns this specific formulation in which slight variations from the idealized, supposedly identical, sequence of rules and principles would preclude the acquisition of a child’s first language. I argue for a biologically plausible Universal Grammar in Chapter 5 of Uniquely Human that would take account of the fact that the genetic endowments of children clearly vary. Unfortunately, part of the discussion is in the footnotes to that chapter and Lord Zuckerman may have overlooked my proposal that Universal Grammars consist of “…loosely specified, redundant genetically transmitted information.” (p. 181) This proposal appears to be making some headway among theoretical linguists. Indeed, genetically transmitted Universal Grammar would predict variation in linguistic ability among individuals (analagous to color perception deficiencies); detailed studies which we have conducted at Brown University show differences in speech perception that may have a genetic basis. Myrna Gopnick at McGill University has found similar syntactic deficits.
Linguists like Noam Chomsky and Derek Bickerton, who claim that the brain bases of syntax are autonomous, language-specific, mechanisms may have a problem with this revised, biologically plausible version of Universal Grammar, since it places a greater load on general cognitive processes in the acquisition of language. However, there may not be as great a gap between certain aspects of “non-linguistic” cognition and language as theoretical linguists have supposed. Bilingual children consistently show accelerated development in abstract reasoning that appears to reflect their acquisition of different abstract rule-governed systems governing syntax and morphology. Vocabulary and real-world knowledge are linked, and “general” cognitive processes such as imitation and associative learning clearly play a role in the acquisition of language. My comment that “The acquisition of a child’s first language would then involve the interplay of general cognitive ability and the innate language-specific information loosely coded in the brain’s Universal Grammar” (p. 180) is consistent with present data.
Indeed, the major premise of my book, which is obscured in Zuckerman’s review, is that evolution for rapid vocal communication produced brain mechanisms that yield cognitive as well as syntactic abilities qualitatively different from those of all other living species and archaic hominids. A wide variety of neurophysiologic data demonstrate that the brain mechanisms that regulate human speech and syntax also enhance human cognitive ability. Areas of the brain like the prefrontal cortex are essential for human syntax, but prefrontal cortical activity also is essential for “abstract” cognitive activity. Many different parts of the brain that are involved in both language and cognition have become enlarged and restructured in the course of evolution. Phylogenetically older parts of the human brain such as the basal ganglia, as well as the traditional “language areas” of the neocortex (Broca’s and Wernicke’s), enter into speech, syntax and cognition. Moreover, Broca’s area, which many suppose to be dedicated exclusively to language, is also involved in the regulation of precise, lateralized hand maneuvers; its evolutionary history appears to start with adaptations for manual dexterity. The same “preadative” process that Charles Darwin invoked in On the Origin of Species to explain the evolution of the lungs of terrestrial animals from the swim bladders of fish, wherein an “organ might be modified from some other and quite distinct purpose” (1859, p. 190) appears to apply to Broca’s area. In other words, the distinction between modern humans and archaic hominids like Homo erectus and the Neanderthals cannot, as Bickerton proposes, be reduced to a neocortical language-specific “syntax organ” that we acquired by means of an abrupt evolutionary event. The evolution of human language probably is the result of a sequence of happenstance circumstances and natural selection, the processes that Darwin proposed over 100 years ago, rather than the Bickerton-Chomsky saltation.
Furthermore, the social attributes that also make humans unique, such as the potential for altruistic behavior, also derive from our enhanced cognitive and linguistic ability. And that is why the evolution of human language is an issue of scientific interest (despite Noam Chomsky’s ukase concerning its insignificance), for it undoubtedly accounts for how and why we differ from other creatures.
Professor and Chairman
Department of Cognitive and
Providence, Rhode Island
To the Editors:
The six-page review of five books on primate behaviour by Lord Zuckerman claimed to address a major philosophical issue but instead found itself bickering, spiteful, needlessly personal, and blind to the good in the works reviewed. I write to set the record straight.
If Jane Goodall does not conform to the standards of objectivity Zuckerman would wish to see, that is because she is interested in the personality differences of her chimpanzees, as a primary explanatory device for their behaviour. It is not for want of being able to be objective. The approach Zuckerman objects to is adopted because without it she is unable to explain the events she observed. This is not a weakness. Nor is “anthropomorphism” (“Jane Goodall is…overwhelmingly anthropomorphic,” p. 44) necessarily a term of abuse. The vaunted separateness of man from all other species animals, of which Zuckerman makes so much play, may indeed as he says be largely due to our use of syntactical language. Personality is not a product of syntactical language. Anthropomorphic description, sensitively used, can contribute to our understanding of chimpanzees. We certainly do not know enough to state categorically that it cannot.
In his dismissive treatment of the work of Cheney and Seyfarth Zuckerman errs again. He seems blind to this advance in our understanding of the thought processes of another species. The methods used in this study are so sophisticated and carefully contrived that the results cannot be readily dismissed. The authors have shown that in particular, very clearly defined (and often experimentally designed) field situations, the monkeys they observed behaved as if they were acting on the basis of particular pieces of stored knowledge, without which they could not have responded in the ways they did. These demonstrations were the result of years of work and are convincing. The animals behaved as if they knew. AS IF. Did they actually know? Cheney and Seyfarth are as completely aware as Zuckerman that we can never be sure what goes on in the mind of another species. Hence their carefully worded caveats, which Zuckerman dismissively calls “negative statement(s)” (p. 47). These caveats do not satisfy Zuckerman, but then what would? He seems already to have prejudged the issue.
Institute of Biological Anthropology
University of Oxford
Lord Zuckerman replies:
I realize that I did not deal with the question posed by Professor Terrace in his opening paragraph in terms as precise as those which he has used. Had I tried, I should not have got far, partly at least because I regard the exact “how and why” of the emergence of Homo erectus as a question that belongs as much to the world of speculation as to that of science. No one knows how many million years it took for natural selection to transform some speechless anthropoid stock into beings whom we would unquestionably have designated human. Even the question of what that stock was, or whether it was single or plural, is as controversial an issue today as it was more than fifty years ago—and as I suspect it always will be.
But Terrace is clearly right in contending that language is something that developed part and parcel with all the other changes that were occurring as man evolved into what he is, and that, in all logic, rules of grammar and syntax would have been adaptively meaningless had their emergence preceded that of the lexical component of language, of individual words with referential meanings. Presumably the semantic component was at first confined only to the relatively few things that were significant to food-gathering and hunting peoples. But at what point, and how gradually, grammar and syntax came on the scene because of the additional adaptive value of joining lexical items in ways that multiplied the meanings that they conveyed can, I imagine, only be a matter for speculation. Nor is it necessary to suppose that grammar and syntax emerged fully blown either in the way in which we know them, or in a form that imposed itself rigidly on the many languages that developed as our primitive ancestors spread into, and then became isolated from one another in different parts of the globe.
I am glad that he has also reminded us that infants can think before they learn to speak, and that in contrast to dubious and endless anecdotal speculation, there are several experimental studies which show that animals can “think,” even if not, as does man, through the vehicle of language. Were Gilbert Ryle, author of The Concept of Mind, still alive, he might well ask what I mean by using the word “think” in the context of this discussion. I therefore fully agree with Terrace that providing a scientific answer to the question of how an animal thinks without language is no easy undertaking.
In the search for an answer, I have often wondered why students of animal behavior have not used as subjects for experimental study such everyday situations as the inter-relations of man and dogs. For example, some process of “thought,” however defined, must surely underlie the behavior of a good sheepdog when, in a situation that is varying all the time, and in response to signals from its owner, it maneuvers scattered sheep through a gate. Even more do I feel that some kind of “thought process” is at work when two or three sheepdogs cooperate in herding scores, or even hundreds, of sheep scattered over a hillside to the same enclosure and through the same dipbath—with the whole operation proceeding without the dogs being rewarded during its course. Whatever could be learnt about animal cognition and communication by strict experimental study of such everyday operations would surely outweigh in scientific value the scores of anecdotes about the intelligence of dogs by which the subject has been encumbered over the years.
So far as I can see, there is little in what Professor Lieberman writes on which I need comment. As I made plain, I have always assumed that all biologists accept that variability, deriving from genetic inheritance, is the “material” on which natural selection operates. Insofar as I understand him, Lieberman believes that the concept of a genetically based “universal grammar” or “language organ” as formulated by Noam Chomsky does not take proper account of this evolutionary truism. As a specialist in linguistics, his argument is, therefore, not with me but with Chomsky.
All that I dare say is that I would find it difficult to believe that a “language organ” emerged in the course of evolution fully blown in the way that grammar and syntax govern the exchanges that take place in the columns of The New York Review. And to return to what Terrace writes, words with referential meaning, however few, must surely have been there before rules of grammar emerged. Once there, I have no difficulty in believing that they became more complex as their adaptive value increased. In the present state of knowledge, I would also believe it prudent to accept Lieberman’s statement that “the human brain cannot be fractionated into strictly linguistic and cognitive organs.” Neuroanatomy and physiology have made remarkable progress in recent years, but we are still far from precise neural explanations, either of language or of variations in human intelligence.
And that brings me to anthropomorphism and Vernon Reynolds’s emotional condemnation of my review. The objectivity which he correctly implies that I believe to be essential in scientific discourse presupposes that observations and conclusions can be formulated and made public in a way that allows them to be either validated or proved false, thus excluding those which, by their nature, fail to allow this criterion to be met. We have recently had an example of the scientific process properly at work in the test of the highly publicized claims made by two scientists about “cold fusion,” which a number of other physicists then failed to substantiate in experiments that duplicated the conditions that had led to the original claims being made.
Reynolds writes that I treat the word “anthropomorphism” as a term of abuse. He is wrong. In the study of animal behavior I regard anthropomorphism as negating an essential element of scientific method, since by its very nature one person’s interpretations of something an animal may be doing can be arbitrarily controverted by another’s alternative interpretation—and with no means available to reconcile their divergent views. For example, when Jane Goodall says that she is able to share the feelings of a female chimpanzee in this or that situation, she is merely projecting onto the animal, about whose feelings she can know nothing, what her own would be in a comparable situation. Another animal observer might well deny the parallelism. In the many years in which I was engaged in active research, I “knew” several chimpanzees, as well as scores of monkeys and baboons, but the fact that I was aware of their “personality differences” did not prove “a primary explanatory device for their behavior”—whatever Reynolds may mean by these words.
Moreover, contrary to what he writes, the fact that Cheney and Seyfarth are to be commended for the arduous work they did in the field does not mean that they added to our understanding of the “thought processes” of another species. Cheney and Seyfarth themselves denied having done this when they wrote—in a passage that I quoted in my review—“in the absence of some accessibility to his own mind, it is difficult to see how a monkey could distinguish between his own thoughts and beliefs and the thoughts and beliefs of others.”
I was unfamiliar with Reynolds’s own ethological writings until I read his commentary on my review. I now see that he has been anything but consistent in his views about anthropomorphism. In the introduction to a volume entitled The Meaning of Primate Signals, of which he was co-editor with Ron Harré (Cambridge University Press, 1984), one reads that “We cannot allow ourselves the luxury of unthinking anthropomorphism.” Again, in the opening paragraph of Chapter 8 of the book, headed “The inevitability and utility of anthropomorphism in descriptions of primate behaviour,” Pamela J. Asquith writes that anthropomorphism “has occasionally been defended, but more often warned against by ethologists,” citing among those who have issued this warning not only Niko Tinbergen—who, with the more colorful Konrad Lorenz, was one of the pioneers of modern ethology—but, strangely, Reynolds himself. Anthropomorphism may add charm to the writings of ethologists, but not, I fear, scientific respectability.
Terrace, H.S., Nim (Knopf, 1979). ↩
Terrace, H.S., “In The Beginning Was The ‘Name,”‘ American Psychologist, Vol. 40, 1985, pp. 1011–1028. ↩
Bruner, J.S., Child’s Talk (Norton, 1983). ↩
Roitblat, H.L., Bever, T.G., and Terrace, H.S., Animal Cognition (Lawrence Erlbaum Associates, 1984). ↩
Terrace, H.S., “Animal cognition: thinking without language,” Philosophical Transactions of Royal Society (London) B, Vol. 308, 1985b, pp. 113–128. ↩