Studying the Thinking of Non-Human Animals

WILLIAM BECHTEL

Department of PhilosophyGeorgia State UniversityAtlanta, GA 30303, U.S.A.

A Review of Daisie Radner and Michael Radner, Animal Consciousness,Promethius Press, Buffalo, New York, 1989, 253 pp., $42.95 (cloth).

Animal Consciousness is really two books. One is situated primarily in the 17thcentury and sets out to declaw Descartes's thesis of the "beast-machine". Theother focuses primarily on 20th century empirical research directed at the mentallives of animals and tries to defend attributions of consciousness to animals a laGriffin (1984). Both books are of much interest, but to my mind the first isclearly the superior.

The Radners' goal in the first book is to expose and discredit the unarguedassumptions in Descartes's arguments against animal thinking. This is importantsince we still live in the shadow of Descartes, and his approach still definesmany of the issues we consider. Moreover, on the question of animal thinking,Descartes's influence may still weigh on many who have repudiated his dualism.As the Radners make clear, the issue of whether animals can think can be arguedwhether or not one accepts that thinking requires an immortal soul. (TheRadners do note, though, that for some 17th century thinkers the reluctance toattribute thinking to animals was precisely a theological concern that suchattributions would also attribute a soul to them.) What is central to the Cartesiananalysis of animal thinking is the question of consiousness. Thinking, forDescartes, is defined in terms of consciousness, while consciousness itself is leftundefined.

Many contemporary thinkers are willing to attribute thought to animals, butnot consciousness. This is because of the baggage consciousness seems to bringwith it. If our thought is conscious, it seems to entail a kind of introspectiveawareness such that we know the contents of our thought and cannot be wrongabout what these contents are. The Radners not only reject this view, but alsodeny that it was Descartes's. They make a distinction between a form ofconsciousness which takes a mental state as its object and a form of conscious-ness that inheres in the mental state itself. The former involves introspection anddoes not entail the existence of the mental state that is the object of introspec-tion. The second form of consciousness, however, does entail the existence ofthe mental state since being conscious is here treated as part of having thatmental state. They contend that it is the latter situation that Descartes has inmind when he contends that thinking is an activity of which we are conscious.

Biology and Philosophy 7: 209-215, 1992.© 1992 Kluwer Academic Publishers. Printed in the Netherlands.

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But this does not entail introspection or privileged access, because thoseactivities involve having a second mental state whose object is the first mentalstate. The occurrence of such a second-order mental state does not entail theexistence of the lower-level state, and hence there is no privileged introspectiveawareness of our conscious mental states. By so distinguishing forms ofconsciousness, the Radners allow a form of consciousness to be attributed toanimals that does not entail introspection. But unfortunately, once consciousnessis dissociated from introspective awareness, it is far from clear what it involvesand hence what is being attributed to animals.

Fortunately, Descartes's thesis about animal thought does not hinge centrallyon his characterization of consciousness. Rather, it turns on two tests heemployed that purport to show that animals do not think. These tests claim toshow (a) that animals do not use language in ways that are indicative of thought;and (b) that animals, while superior to us in performing some actions, are muchinferior in others. The point of the second test is that if animals achieved theirsuperior performance in some domains by thinking, then they ought to showsuch superior performance in all activities. Since they plainly are inferior insome activities, then their performance is not attributable to reason. This, ofcourse, assumes that the reasoning capacity is all of one type, so that success inreasoning about one type of problem guarantees success in reasoning in otherdomains. It also assumes that exercise of reason is an all or none affair. TheRadners argue quite plausibly, however, that reason can be exercised inrestricted domains using restricted principles, and to discount any use ofreasoning by animals we would have to show that there is no set of reasoningprinciples that could account for animal performance. With regard to Des-cartes's first test, the Radners' show how Descartes attempted to explain thevarious uses of communication systems by animals as expressions of passion.Ultimately, they contend that in order to differentiate human use of languagefrom animal communication, Descartes was forced to an extremely highstandard: the use of language to express pure thought. But, they note, the failureto use language for pure thought does not show that one does not use languageat all, and therefore that one does not have any thought. Hence, the Radnersconclude that neither argument establishes that animals are devoid of thought.

The goal of the second book is to set out a context for a comparative psychol-ogy that adverts in a crucial way to the conscious mental states of animals.Darwin's evolutionary analysis provides the framework for this by constructinga continuity not only in physiology, but also in behavior, between human andnon-human animals. The Radners describe how the discipline of comparativepsychology was rooted in this evolutionary scenario. In this context they offeran interesting and radical reinterpretation of Lloyd Morgan's famous Canon: "Inno case may we interpret an action as the outcome of the exercise of a higherpsychical faculty, if it can be interpreted as the outcome of the exercise of onewhich stands lower in the psychological scale" (Morgan 1894, p. 53, quoted onp. 138). Quite naturally, Morgan has been read as advocating that we assume nomore than is absolutely necessary in the way of cognitive operations to explain a

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particular piece of animal behavior. The Radners surprisingly argue thatMorgan's endeavor was to create an evolutionary continuity so that "Morganneeds to raise some animals up and make sure they stay raised. Thus he has avested interest in failing to explain at least some animals' actions in terms oflower faculties" (p. 139). Unfortunately, they do not develop the argument forthis revisionist interpretation, for they are more concerned with another aspect ofthe Darwinian contribution, one which is far less conducive to any analysis interms of conscious mental states. This is the commitment to a naturalistic,physicalistic analysis of behavior advocated by some of Darwin's supporters.Such a view holds little place for conscious mental states; in the hands ofHuxley it became the basis of a construal of consciousness as epiphenomenal.The Radners relate how anthropomorphic analyses of some early comparativepsychologists, especially those of Margaret Washburn, were opposed by theanti-anthropomorphism of behaviorists and other naturalists who denied theneed to appeal to conscious mental states.

While not endorsing the early traditions of Morgan and Washburn, theRadners clearly favor a perspective that permits attributions of consciousness toanimals in virtue of their brain states: "Moreover, there is no reason whyconscious states - states subjectively experienced by the organism - cannot bepart of the causal network of brain processes" (p. 143). One of the Radners'main strategies for arguing for conscious mental states in animals is to supplyalternative interpretations of the research results that others have advanced todiscredit the mindfulness of animals. They consider, for example, the case of thedigger wasp, who brings a cricket to her burrow, goes inside apparently to insurethat all is well, and returns to get the cricket and take it inside. Fabre (1915)performed the simple experiment of draging the cricket several inches from theburrow. When the wasp reemerged, she found the cricket, but then, rather thanproceeding directly to the burrow, she repeated the inspection step. AlthoughFabre repeated the removal of the cricket forty times, the wasp never wised up,apparently revealing that the wasp was under the control of instinct, notintelligent reason. The Radners' counter strategy is to contend that the wasp'saction can still be construed as rational:

One can easily imagine a case in which it would be wise to repeat forty times or morethe process of looking before you leap. You are on the fifteenth floor of a burningbuilding. A safety net is being held out for you below. Forty times the smoke andfalling debris drive you back. Each time you approach the ledge you check to makesure that the net is still there, for the firemen could have moved it to rescue someoneelse in the meantime. (p. 176)

With this and other examples the Radners' strategy is the same: to show that wecan create a perspective from which the animal's behavior appears rational. Thisseems to provide at best a weak defense of the ability to attribute consciousnessto animals: We can do so if we choose. But why should we do so? If our goal isto attribute cognitive processes to animals, there is good reason to do so:increasingly we have evidence about the behavior of animals that requirespostulating internal information processing in them as in humans. Thus, there is

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a growing body of research in animal cognition (see Roitblat 1987). This work,regrettably is not discussed by the Radners, in large part since their goal is toargue for conscious mental activity, and in studies of animal cognition, as inthose of human cognitive science, the focus is not primarily on conscious mentallife. The major thrust of the second book is therefore found in a chapter entitled"Making Room for Consciousness." Here the Radners set out to save DonaldGriffin's (1984) appeal to animal consciousness from the charges that suchappeals are ill-defined, untestable, and superfluous. Against the charge thatanimal consciousness is ill-defined, the Radners argue principally against thecharge that assuming conscious states requires assuming that they are infalliblyintrospectable. They reiterate the argument drawn from their analysis ofDescartes that introspective consciousness is different from the consciousnessthat is part of a thought. The former involves a second thought, and is onlyfallibly related to the first thought. The latter does not involve introspection, buta direct awareness. For someone who does not understand what is being claimedwhen consciousness is attributed to a state, this will hardly help. What we needto know is how this consciousness that is intrinsic to the state makes the statedifferent from other states.

Moreover, appealing to this intrinsic character of conscious awareness makesit more difficult to show how the claim that these states are consciousness istestable and not superfluous. In discussing the testability claim, the Radnersintroduce the problems of inverted spectra and absent qualia, familiar tophilosophers of psychology. The Radners fail to note, however, that theseproblems are usually introduced not by those seeking to deny consciousness, butrather by those who believe that consciousness is inherently left out of physicalis-tic accounts of mental states. These arguments are being pressed into a foreigntask when they are construed as arguments that animals are not conscious in thesense of having qualitative character to their mental states. In any case, theRadners respond to such examples by contending that they unfairly assume thatconsciousness can be disconnected from brain processes. In the context of thehuman case, I concur that this is a useful response. But to make it successfully,one is required to show that phenomenal consciousness is actually complex, andthat it decomposes in exactly the way we would expect if it were indeed aproperty of the physical brain. (For an example of how to do this in the case ofcolor perception, see Hardin 1988.) But in the human case this is possiblebecause we can query people as to the features that are present in phenomenalawareness. But this is exactly what we cannot do with animals. To make theattribution of consciousness to their brain states we need some avenue forproducing evidence. Rather than suggesting a way to procure such evidence, theRadners appeal to the lack of a physiological theory of consciousness to explainthe lack of evidence. The situation, they claim, is comparable to the situation ofarguing for evolution without the theory of natural selection. It is only once aplausible theory is developed that we will be able to martial supportingevidence.

The Radners' case here is weak, but it gets even weaker when they consider

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the charge that consciousness is superfluous. They simply contend that ifconsciousness is a causal factor, then it is not superfluous and reject any claimthat the causal factor might be present without consciousness as an unarguedassumption. They therefore conclude that we do not need to insist on analyzingbehavior without consciousness: "There is room for consciousness if we arewilling to make room" (p. 208). This is hardly the sort of argument that willmotivate someone to take consciousness seriously. What skeptics of attributingconsciousness to human or non-human animals seek is some account of whatconscious contributes to the organism.

It is regrettable that the Radners did not try to mount, or at least outline howwe might mount, a positive case that consciousness is needed in an explanationof animal behavior. We might begin with cases in which animals might beshown to suffer deficits comparable to those faced by humans when deprived ofconsciousness. In humans, the phenomenon of blindsight constitutes a case inwhich much of the information provided by normal vision is available to thesubject, but in which a lesion has destroyed the subject's conscious awareness.Thus, a patient will report not being able to see in a certain area, but when askedto guess where something might be, will be reliably accurate (Weiskrantz 1986).Nicholas Humphrey reports that a similar situation arose when the striate cortexof a monkey was removed. The animal acted as if she could not see, and had tobe taught that she was in fact receiving sufficient visual information to be able toguide her movements in her environment (Humphrey 1974). Given thesimilarities in the visual systems of monkeys and humans, it at least seems to beplausible that the monkey had been deprived of conscious perception, and had torely on alternative, non-conscious information sources. As in the human, the lossof the conscious information processing channel clearly has induced a be-havioral deficit. This is just one of many ways one could presumably investigatethe difference conscious information processing makes to non-humans as well ashumans.

In this very brief sketch of how we might investigate consciousness inanimals empirically, I have implicitly put the discussion in a different context,that of information processing, not that of thinking. The notion of thought is partof our folk idiom for characterizing people, an idiom that is extremely fruitfuland important, but not one intended for characterizing internal processes thatunderlie human behavior, including thinking. When we want to explain folkprocesses which are performed by people we need to switch to an appropriateinternal processing language, such as that emerging in cognitive science. Muchinformation processing may occur in a person without the person being aware ofit. I have therefore introduced a distinction that is not in the Radners' account:that between conscious and unconscious information processing. Some informa-tion processing influences the conscious experience of a person, other informa-tion processing does not. Understanding what makes conscious and unconsciousinformation processing different, and the different consequences of each type ofinformation processing, has become a point of research in human cognitivescience, and while similar investigations will be more difficult in animals, there

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is no reason to preclude them.I have left to last a discussion of the Radners' analysis of research on animal

language. The link between language and consciousness stems from Descartes'sconnection of thought with consciousness and his use of the claim that animalscannot use language to establish that they do not think. Since many theoriststoday dissociate thought and consciousness, the relevance of the animallanguage work to consciousness is less clear. But here the Radners, by ignoringthe past ten years of research on animal language, have left themselves in anapologetic position, where there are now grounds to make a powerful positivecase for the continuity of cognitive processes. The Radners relate the attempts inthe 1970s by the Gardners, Premack, and Rumbaugh to teach American SignLanguage or artificial languages to common chimpanzees (pan troglodytes) aswell as the criticisms advanced against this work as a result of Terrace'sresearch with Nim. They also make a number of solid arguments themselves,noting especially that the communicative endeavors in which these chimpanzeeswere asked to engage were not chosen by the chimpanzee as activities of interestto it. It thus seems very peculiar that they have chosen not to discuss the onemajor chimpanzee project during the 1980s, much of which focused on exactlythat concern.

After Savage-Rumbaugh (see review in Savage-Rumbaugh 1986) haddeveloped a technique for teaching referential use of lexigrams to two commonchimpanzees (who in fact used these in activities of interest to them, andintroduced lexigrams for items they wanted to talk about), she attempted toreplicate the project with a bonobo chimpanzee (pan paniscus). Discovering thatone bonobo chimpanzee (Kanzi) had already learned the use of lexigrams fromobserving attempts to teach lexigrams to his mother, Savage-Rumbaugh changedstrategies. She and other caregivers did not try to condition Kanzi to uselexigrams, but used them in his environment to negotiate such things as where inthe woods they might go, what they would take with them, and what activitiesthey would perform. Kanzi gradually began to engage in these communicativeendeavors himself, using lexigrams to express his desires and to negotiateactivities. Savage-Rumbaugh, McDonald, Sevcik, Hopkins, and Rubert (1986)show that in this way Kanzi learned the referential function of a number oflexigrams, understood the referential function of still others he did not use, and,most surprising, understood the referential function of English words.

These tests were conducted in rigorous blind conditions (e.g., using syn-thesized speech played to Kanzi through headphones so that no humancaregivers could know the question put to Kanzi), and reveal what can belearned by a non-human primate when exposed to a language system that isproviding information of interest to it. More recently, Kanzi has demonstratedcomprehension of a number of novel English sentences (Savage-Rumbaugh1990). The Radners' claim that "with primate language research, the more thedata are examined the less impressive they are" (p. 160) is utterly unfair to thelast decade of data, which they fail to cite. This is not, however, to insist thatwork with non-human primates is the only way to explore linguistic capacities

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of animals. The increasing work on the natural communication systems ofanimals in their normal habitats, which the Radners advocate, is also important,and the two research endeavors are actually complementary. (For a collectionthat integrates both lines of research, see Roitblat, Herman, and Nachtigall1991.) One reason Savage-Rumbaugh explored the capacities of the bonobo in ahuman language environment is that bonobos exhibit a much greater use ofgesture and of attention to the natural communications of other members of theirspecies than do common chimpanzees. Given the importance human develop-ment psychologists are now giving to gesture as a building block in acquisitionof human languages, it seems highly plausible to see this natural ability togesture as a part of the emergence of language, and to investigate its potential.

In the end, Animal Consciousness does more to raise issues, than settle them.The analysis the Radners' offer of the Cartesian injunctions against animalthinking is a useful therapeutic to our intellectual legacy and helps to free usfrom its grip. But the discussion of recent research is at best suggestive, and failsto carry forward the critical analysis that would make the attribution of con-sciousness and thought to animals compelling, especially to philosophers. Thisis regrettable, since this case needs to be made, and the evidence for making thecase is growing rapidly in the allied fields of ethology, comparative psychology,and animal cognition.

REFERENCES

Fabre, J. H.: 1915, The Hunting Wasps, A.T. de Mattos (trans.), Dodd, Mead, New York.Griffin, D. R.: 1984, Animal Thinking, Harvard University Press, Cambridge, Mass.Hardin, C.L.: 1988, Color for Philosophers, Hackett, Indianapolis, IN.Humphrey, N. R.: 1974, 'Vision in a Monkey Without Striate Cortex', Perception 3,

241-255.Morgan, C.L.: 1984, An Introduction to Comparative Psychology, Walter Scott, London.Roitblat, H. L.: 1987, An Introduction to Comparative Cognition, Freeman, New York.Roitblat, H. L., L. Herman, and P. Nachtigall: 1991, Language and Communication:

Comparative Perspectives, Lawrence Erlbaum Associates, Hillsdale, New Jersey.Savage-Rumbaugh, E. S.: 1986, Ape Language. From Conditioned Response to Symbol,

Columbia University Press, New York.Savage-Rumbaugh, E. S.: 1990, 'Language as a Cause-Effect Communication System',

Philosophical Psychology 3, 55-76.Savage-Rumbaugh, E. S., K. McDonald, R. A. Sevcik, W. D. Hopkins, and E. Rubert:

1986, 'Spontaneous Symbol Acquisition and Communicative Use by PygmyChimpanzees (Pan Paniscus)', Journal of Experimental Psychology: General 115,211-235.

Weiskrantz, L.: 1986, Blindsight: A Case Study and Implications, Oxford UniversityPress, Oxford.

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