- Email: [email protected]
Animal cognition
J. Social
Bid.
SWUC/.
1986 9. 91-103
Book Reviews Animal Cognition. Edited by H. L. Roitblatt, NJ: Lawrence Erlbaum Associates, 1984. Animal
Thinking.
T. G. Bever and H. S. Terrace. Hillsdale,
By R. Griffin. Cambridge, MA: Harvard University Press, 1984. Animal
thought
What goes on in another animal’s mind? The question is obviously sensible and profound, and one might reasonably expect men and women who call themselves animal psychologists to be able to provide some answers. But while many of us have been fascinated by such questions, few have found it possible to render such questions tractable. At best, we do what we can with manageable questions and leave the deep ones for after-hours (if then). Is the question beyond the scope of scientific inquiry? It depends what you mean, and who you ask. Before behaviorism was dethroned, the scientific consensus would have been simple: ‘no’. But the answer is simple no more. Cognitive psychology has largely supplanted behaviorism, and animal cognition has become a legitimate and productive object of investigation. Many of the leading investigators conferred at Columbia University in June, 1982, and Animal Cognition, edited by Roitblatt, Bever, and Terrace, is the result. The book can be recommended to anyone who wants a good survey of what is happening in the field. However, the reader must understand, as many contributors to the book affirm, that the study of animal cognition is not the same as the study of animal consciousness; indeed, according to Terrace, the ‘ghosts of consciousness and introspection’ have been ‘exorcised’ from the study of animal cognition, and are in any case irrelevant (p. 8). In contrast, D. R. Griffin’s Animal Thinking seeks to convince us that animal consciousness is not only relevant, but studiable and important. All parties accept that the study of animal cognition is the study of hypothetical psychological processes underlying animal behavior: memory, perception, concept formation and categorization, spatial representation, time estimation, and so on. Of special interest is the development and testing of structural models of mechanisms and processes. In the words of one current practitioner, the modern approach ‘combines the rigorous experimental design of the behaviorists with the empirically testable speculation of the structuralists’ (Zentall, Hogan & Edwards, p. 389; all citations not explicitly attributed to Griffin are from Animal Cognition). The approach is thus openly derivative of human cognitive psychology and traditional experimental animal psychology, and while some of the work contained in the book is therefore somewhat slavish and uncreative, a good deal of first rate research and writing is also on display here. Besides the cognitive slant which unifies Animal Cognition there is, as a minor theme, 014&1750/86/010091
+
13 %03.00/O
0
1986 Academic
Press Inc.
(London)
Limited
92
Book Reviews
an attempt to incorporate a biological perspective. Psychologists and biologists have much to contribute to each other these days, especially in light of behavioral ecology’s increasing emphasis on decision-making, social-cognition, and context-sensitivity. But as Kamil points out, the opportunity has not been exploited adequately. Although Balda’s suggestive analysis of the Acorn Woodpecker’s spectacular memory for food caches is a notable and promising exception, the species examined in Animal Cognition are few and familiar (predominantly pigeons, rats, and monkeys), and most work still consists of new variations on old learning paradigms. (Operant methodologies in particular are, ironically, proving their worth in the investigation of issues they were originally designed to avoid.) Nonetheless, at least one biological insight emerges repeatedly: impressive cognitive adaptations evolved in nature may fail to emerge in standardized laboratory situations. Some investigators greet this realization with dismay, others shift their research emphases from ‘elegant simplicity’ to ‘exquisite complexity’, and others, notably those studying acquisition of ‘natural concepts’ in pigeons address the issue of ‘naturalness’ directly. Among these, Herrnstein’s contribution is stellar, exemplary, and relevant to the question of animal consciousness. Categories that are fairly easy to describe physically do not seem to be significantly easier for animals, and may even be harder, than categories that are hard to describe in those terms. For
example, pigeons appear to find patches of colored light a harder category to form than photographs of trees . . . . That no man-made machine behaves this way suggests that existing machines differ in some basic way from living organisms. as far as categorization is concerned. The likeliest
difference
is in the perceptual
dimensions
themselves
(pp. 257-258).
Now, animal consciousness, if it exists, must be ‘filled’ by the natural concepts, perceptual dimensions, and cognitive structures revealed in studies of animal cognition. For this reason, the work described in Animal Cognition will be of interest to anyone seeking insight into the nature of animal consciousness. However, D. R. Griffin attempts to extend such work in two directions. First, he considers a wider variety of animals, observed under naturalistic circumstances. And second, he endeavors to ‘come to grips with the subjective aspects of animal consciousness’ (p. 3). Each attempt is worthy of comment. Griffin comes to the study of animal psychology after a distinguished career as a biologist, and most of his book reviews some of the more impressive behavioral feats of vertebrates and invertebrates alike. For example, the dance language of the bees is reviewed, as is recent work on putatively referential communication in vervet monkeys. Animal Thinking is also filled with many less well-known cases, such as that of the assassin bug which camouflages itselfchemically by gluing bits of termite nest to its body, so as to capture, kill, and consume the body fluids of a termite worker. Then, the assassin bug pushes the empty exoskeleton of its first victim into the nest opening, and by jiggling it, ‘calls’ out another worker, who eventually serves as bait for the next victim, and so on. Such observations certainly provoke thought, but Griffin’s point is that they may also exemplify thought. He writes, When chimpanzees fashion sticks to probe for termites [it] is considered one of the most convincing casesof intentional behavior yet described for nonhuman animals. When McMahan [ 19821discovers assassinbugs carrying out an almost equally elaborate feeding behavior. must we assume that the insect is only a genetically programmed robot incapable of understanding what it does? Perhaps we should be ready to infer conscious thinking whenever any animal shows such ingenious behavior, regardless of its taxonomic group and our preconceived notions about limitations of animal consciousness(p. 124). Here, then, is the strength and the weakness of Griffin’s book. He successfully identifies and undermines many common prejudices about animal consciousness-that
Book Reviews
93
there are principled grounds for assuming that large vertebrate nervous systems and/or the capacity for learning are necessarily prerequisites for consciousness, that ‘simple’ organisms are behaviorally or cognitively simple, indeed, that we know anything with certainty about the distribution ofconsciousness in the animal kingdom-but he also fills his book with commentaries which often seem gratuitious and necessarily beyond test. Thus, describing the construction of bubble nets by humpback whales, he writes ’ . . . it seems likely that they are anticipating the taste of food and the sensation of swallowing something more than sea water’ (p. 51). Of course it ‘seems likely’. The question is, however (and this is where Griffin’s second goal comes in), whether such intuitive speculations advance the scientific investigation of these issues? Perhaps. Griffin’s speculations lead him to review possible scientific lines of attack ably and clearly, and he identifies several which do in fact show promise, at least for dealing with some of our closer and more intelligent relatives. He discusses, for example, the possibility that we might eventually identify electrophysiological correlates of consciousness in our own species; these could then be used, along with corroborative behavioral evidence, to identify (or disconfirm) probable cases of conscious thought in other primates. (It is equally possible, I would add, that human psychologists might objectively identify cognitive processes correlated with conscious experience in humans, and that these might then be sought in animals as well.) The prospect Griffin finds most promising is that animal communication will eventually provide a ‘window on animal minds’. After all, it is through communication that we obtain our most convincing evidence that other humans are in fact thinking, feeling beings. The study of specialized communicative behavior between animals is more promising than learning experiments because it seems to have evolved to serve a purpose quite similar to what we want to use it for-namely, conveying to another animal the content of the communicator’s thoughts and feelings. If its thoughts do have significant content, eavesdropping on its communicative behavior under favorable conditions might tell us something about that content (p. 163).
A learning psychologist’s rebuttal can be found in Wasserman’s chapter in Animal Cognition, but it should also be noted that contrary to Griffin’s assertion, the adaptive function of communicative behavior is almost certainly to allow animals to benefit themselves by influencing the behaviors of others. Accurate conveyal of thoughts and feelings may be an occasional means to that end. Or it may nor be. That is the question, and there is the rub. The difficulty of arriving at definite conclusions in this business is well illustrated by considering one argument Griffin often invokes: consciousness must exist in animals because it would be so useful. But useful in what way? Griffin suggests that consciousness is an efficient means by which genes might produce adaptive behavior. Thus, discussing the behavior of leaf-cutter ants, he suggests that it may be ‘plausible to suppose that their DNA programs the development of simple generalizations such as “Search for juicy green leaves” or “Nibble away bits of fungus that do not smell right”, rather than specifying every flexion and extension of all six appendages’ (p. 105). An interesting but problematic idea. First problem: how the nervous system translates such directives into movements remains unexplained. On the other hand, it is true that high-level programming languages are useful in artificial intelligence, and Griffin may well be right in supposing that they underlie the programming of natural intelligence as well. Some principled arguments would be useful here (c.f. Bever’s chapter in Animal Cognition). Second, as Griffin acknowledges, the idea leaves us without a
94
Book Reviews
rationale for a consciously experienced, rather than unconsciously implemented, action language. On the other hand, rationale or no, our species does it consciously at least some of the time. Thus, here is one of many instances in which Griffin has raised an issue which is clearly worth further consideration, even if the resolution is far from clear. His book is a useful compendium of such issues, reviewed and assessed with uncommon common sense. Though he risks the charge, Griffin is neither naive nor doctrinaire. His book advocates open-mindedness and further investigation, not accession to the principle that animals are conscious, and his own conclusion seems to me the appropriate one: ‘It remains to be seen whether future research will build up a fully credible fabric of data and interpretations supporting hypotheses about animal consciousness, or whether the accumulating evidence will turn out negative, or inconclusive and unconvincing’ (p. 208). Griffin does demonstrate clearly that many of our assumptions need reexamination, and that questions about animal consciousness can at least inspire interesting and testable hypotheses, perhaps including the hypothesis that animals are conscious. His book is good reading even if it advances the field only a little. One salutory effect of Animal Thinking might well be to inspire other behavioral scientists, including some whose work is to be found in Animal Cognition, to give more thought to questions they have shied away from for too long. And thinking in scientists even if not in other animals, is surely a good thing. Jonathan Schull Department of Psychology, Haverford College, Haverford, PA 19041, USA
References McMahan, E. A. (1982). Bait-and-capture strategy of termite-eating assassin bug. Insectes Sociaux 29: 346-35 1.
Surface and Depth in Political Biology: A Review Essay. (Politics and Biology: Contributions to the Life-Sciences Orientation of the Social Sciences). By Heiner Flohr and Wolfgang Toennesmann. Berlin and Hamburg: Paul Parey, 1983, 222 pages. There may seem little point to an extensive review of a new book, published in German in Germany, for a journal whose readership is largely composed of people whose native tongue is English. For at least three reasons, it is worth it. The most important one is to see what writers in political biology have contributed to a fundamental understanding of political behavior. Another is to see what has been lacking in the development of the field. And a third to see how European social scientists look at this new and rankly growing field of intellectual endeavor. The task is rendered easier by the fact that all but two of the thirteen essays in this German book are by Americans and one Canadian, all of whom have written before on political biology. Authors of five of the essays (Corning, Laponce, Masters, Peterson, and G. Schubert) report that their contributions are revised versions of essays published as far back as 1974 and as recently as 1981. We may nevertheless suppose that all the essays represent current thinking of the writers.
Bid.
SWUC/.
1986 9. 91-103
Book Reviews Animal Cognition. Edited by H. L. Roitblatt, NJ: Lawrence Erlbaum Associates, 1984. Animal
Thinking.
T. G. Bever and H. S. Terrace. Hillsdale,
By R. Griffin. Cambridge, MA: Harvard University Press, 1984. Animal
thought
What goes on in another animal’s mind? The question is obviously sensible and profound, and one might reasonably expect men and women who call themselves animal psychologists to be able to provide some answers. But while many of us have been fascinated by such questions, few have found it possible to render such questions tractable. At best, we do what we can with manageable questions and leave the deep ones for after-hours (if then). Is the question beyond the scope of scientific inquiry? It depends what you mean, and who you ask. Before behaviorism was dethroned, the scientific consensus would have been simple: ‘no’. But the answer is simple no more. Cognitive psychology has largely supplanted behaviorism, and animal cognition has become a legitimate and productive object of investigation. Many of the leading investigators conferred at Columbia University in June, 1982, and Animal Cognition, edited by Roitblatt, Bever, and Terrace, is the result. The book can be recommended to anyone who wants a good survey of what is happening in the field. However, the reader must understand, as many contributors to the book affirm, that the study of animal cognition is not the same as the study of animal consciousness; indeed, according to Terrace, the ‘ghosts of consciousness and introspection’ have been ‘exorcised’ from the study of animal cognition, and are in any case irrelevant (p. 8). In contrast, D. R. Griffin’s Animal Thinking seeks to convince us that animal consciousness is not only relevant, but studiable and important. All parties accept that the study of animal cognition is the study of hypothetical psychological processes underlying animal behavior: memory, perception, concept formation and categorization, spatial representation, time estimation, and so on. Of special interest is the development and testing of structural models of mechanisms and processes. In the words of one current practitioner, the modern approach ‘combines the rigorous experimental design of the behaviorists with the empirically testable speculation of the structuralists’ (Zentall, Hogan & Edwards, p. 389; all citations not explicitly attributed to Griffin are from Animal Cognition). The approach is thus openly derivative of human cognitive psychology and traditional experimental animal psychology, and while some of the work contained in the book is therefore somewhat slavish and uncreative, a good deal of first rate research and writing is also on display here. Besides the cognitive slant which unifies Animal Cognition there is, as a minor theme, 014&1750/86/010091
+
13 %03.00/O
0
1986 Academic
Press Inc.
(London)
Limited
92
Book Reviews
an attempt to incorporate a biological perspective. Psychologists and biologists have much to contribute to each other these days, especially in light of behavioral ecology’s increasing emphasis on decision-making, social-cognition, and context-sensitivity. But as Kamil points out, the opportunity has not been exploited adequately. Although Balda’s suggestive analysis of the Acorn Woodpecker’s spectacular memory for food caches is a notable and promising exception, the species examined in Animal Cognition are few and familiar (predominantly pigeons, rats, and monkeys), and most work still consists of new variations on old learning paradigms. (Operant methodologies in particular are, ironically, proving their worth in the investigation of issues they were originally designed to avoid.) Nonetheless, at least one biological insight emerges repeatedly: impressive cognitive adaptations evolved in nature may fail to emerge in standardized laboratory situations. Some investigators greet this realization with dismay, others shift their research emphases from ‘elegant simplicity’ to ‘exquisite complexity’, and others, notably those studying acquisition of ‘natural concepts’ in pigeons address the issue of ‘naturalness’ directly. Among these, Herrnstein’s contribution is stellar, exemplary, and relevant to the question of animal consciousness. Categories that are fairly easy to describe physically do not seem to be significantly easier for animals, and may even be harder, than categories that are hard to describe in those terms. For
example, pigeons appear to find patches of colored light a harder category to form than photographs of trees . . . . That no man-made machine behaves this way suggests that existing machines differ in some basic way from living organisms. as far as categorization is concerned. The likeliest
difference
is in the perceptual
dimensions
themselves
(pp. 257-258).
Now, animal consciousness, if it exists, must be ‘filled’ by the natural concepts, perceptual dimensions, and cognitive structures revealed in studies of animal cognition. For this reason, the work described in Animal Cognition will be of interest to anyone seeking insight into the nature of animal consciousness. However, D. R. Griffin attempts to extend such work in two directions. First, he considers a wider variety of animals, observed under naturalistic circumstances. And second, he endeavors to ‘come to grips with the subjective aspects of animal consciousness’ (p. 3). Each attempt is worthy of comment. Griffin comes to the study of animal psychology after a distinguished career as a biologist, and most of his book reviews some of the more impressive behavioral feats of vertebrates and invertebrates alike. For example, the dance language of the bees is reviewed, as is recent work on putatively referential communication in vervet monkeys. Animal Thinking is also filled with many less well-known cases, such as that of the assassin bug which camouflages itselfchemically by gluing bits of termite nest to its body, so as to capture, kill, and consume the body fluids of a termite worker. Then, the assassin bug pushes the empty exoskeleton of its first victim into the nest opening, and by jiggling it, ‘calls’ out another worker, who eventually serves as bait for the next victim, and so on. Such observations certainly provoke thought, but Griffin’s point is that they may also exemplify thought. He writes, When chimpanzees fashion sticks to probe for termites [it] is considered one of the most convincing casesof intentional behavior yet described for nonhuman animals. When McMahan [ 19821discovers assassinbugs carrying out an almost equally elaborate feeding behavior. must we assume that the insect is only a genetically programmed robot incapable of understanding what it does? Perhaps we should be ready to infer conscious thinking whenever any animal shows such ingenious behavior, regardless of its taxonomic group and our preconceived notions about limitations of animal consciousness(p. 124). Here, then, is the strength and the weakness of Griffin’s book. He successfully identifies and undermines many common prejudices about animal consciousness-that
Book Reviews
93
there are principled grounds for assuming that large vertebrate nervous systems and/or the capacity for learning are necessarily prerequisites for consciousness, that ‘simple’ organisms are behaviorally or cognitively simple, indeed, that we know anything with certainty about the distribution ofconsciousness in the animal kingdom-but he also fills his book with commentaries which often seem gratuitious and necessarily beyond test. Thus, describing the construction of bubble nets by humpback whales, he writes ’ . . . it seems likely that they are anticipating the taste of food and the sensation of swallowing something more than sea water’ (p. 51). Of course it ‘seems likely’. The question is, however (and this is where Griffin’s second goal comes in), whether such intuitive speculations advance the scientific investigation of these issues? Perhaps. Griffin’s speculations lead him to review possible scientific lines of attack ably and clearly, and he identifies several which do in fact show promise, at least for dealing with some of our closer and more intelligent relatives. He discusses, for example, the possibility that we might eventually identify electrophysiological correlates of consciousness in our own species; these could then be used, along with corroborative behavioral evidence, to identify (or disconfirm) probable cases of conscious thought in other primates. (It is equally possible, I would add, that human psychologists might objectively identify cognitive processes correlated with conscious experience in humans, and that these might then be sought in animals as well.) The prospect Griffin finds most promising is that animal communication will eventually provide a ‘window on animal minds’. After all, it is through communication that we obtain our most convincing evidence that other humans are in fact thinking, feeling beings. The study of specialized communicative behavior between animals is more promising than learning experiments because it seems to have evolved to serve a purpose quite similar to what we want to use it for-namely, conveying to another animal the content of the communicator’s thoughts and feelings. If its thoughts do have significant content, eavesdropping on its communicative behavior under favorable conditions might tell us something about that content (p. 163).
A learning psychologist’s rebuttal can be found in Wasserman’s chapter in Animal Cognition, but it should also be noted that contrary to Griffin’s assertion, the adaptive function of communicative behavior is almost certainly to allow animals to benefit themselves by influencing the behaviors of others. Accurate conveyal of thoughts and feelings may be an occasional means to that end. Or it may nor be. That is the question, and there is the rub. The difficulty of arriving at definite conclusions in this business is well illustrated by considering one argument Griffin often invokes: consciousness must exist in animals because it would be so useful. But useful in what way? Griffin suggests that consciousness is an efficient means by which genes might produce adaptive behavior. Thus, discussing the behavior of leaf-cutter ants, he suggests that it may be ‘plausible to suppose that their DNA programs the development of simple generalizations such as “Search for juicy green leaves” or “Nibble away bits of fungus that do not smell right”, rather than specifying every flexion and extension of all six appendages’ (p. 105). An interesting but problematic idea. First problem: how the nervous system translates such directives into movements remains unexplained. On the other hand, it is true that high-level programming languages are useful in artificial intelligence, and Griffin may well be right in supposing that they underlie the programming of natural intelligence as well. Some principled arguments would be useful here (c.f. Bever’s chapter in Animal Cognition). Second, as Griffin acknowledges, the idea leaves us without a
94
Book Reviews
rationale for a consciously experienced, rather than unconsciously implemented, action language. On the other hand, rationale or no, our species does it consciously at least some of the time. Thus, here is one of many instances in which Griffin has raised an issue which is clearly worth further consideration, even if the resolution is far from clear. His book is a useful compendium of such issues, reviewed and assessed with uncommon common sense. Though he risks the charge, Griffin is neither naive nor doctrinaire. His book advocates open-mindedness and further investigation, not accession to the principle that animals are conscious, and his own conclusion seems to me the appropriate one: ‘It remains to be seen whether future research will build up a fully credible fabric of data and interpretations supporting hypotheses about animal consciousness, or whether the accumulating evidence will turn out negative, or inconclusive and unconvincing’ (p. 208). Griffin does demonstrate clearly that many of our assumptions need reexamination, and that questions about animal consciousness can at least inspire interesting and testable hypotheses, perhaps including the hypothesis that animals are conscious. His book is good reading even if it advances the field only a little. One salutory effect of Animal Thinking might well be to inspire other behavioral scientists, including some whose work is to be found in Animal Cognition, to give more thought to questions they have shied away from for too long. And thinking in scientists even if not in other animals, is surely a good thing. Jonathan Schull Department of Psychology, Haverford College, Haverford, PA 19041, USA
References McMahan, E. A. (1982). Bait-and-capture strategy of termite-eating assassin bug. Insectes Sociaux 29: 346-35 1.
Surface and Depth in Political Biology: A Review Essay. (Politics and Biology: Contributions to the Life-Sciences Orientation of the Social Sciences). By Heiner Flohr and Wolfgang Toennesmann. Berlin and Hamburg: Paul Parey, 1983, 222 pages. There may seem little point to an extensive review of a new book, published in German in Germany, for a journal whose readership is largely composed of people whose native tongue is English. For at least three reasons, it is worth it. The most important one is to see what writers in political biology have contributed to a fundamental understanding of political behavior. Another is to see what has been lacking in the development of the field. And a third to see how European social scientists look at this new and rankly growing field of intellectual endeavor. The task is rendered easier by the fact that all but two of the thirteen essays in this German book are by Americans and one Canadian, all of whom have written before on political biology. Authors of five of the essays (Corning, Laponce, Masters, Peterson, and G. Schubert) report that their contributions are revised versions of essays published as far back as 1974 and as recently as 1981. We may nevertheless suppose that all the essays represent current thinking of the writers.