View Full Version : Species of Mind: The Philosophy and Biology of Cognitive Ethology

Monday, May 23rd, 2005, 11:49 PM
Species of Mind:

The Philosophy and Biology of Cognitive Ethology

by Colin Allen (http://grimpeur.tamu.edu/%7Ecolin/) and Marc Bekoff

Department of Philosophy
Texas A&M University
College Station, Texas 77843 USA
Department of Environmental, Population, and Organismic Biology
University of Colorado
Boulder, Colorado 80309-0334 USA


There is a lot of interest in studying the minds of nonhuman animals and in the need for interdisciplinary connections between empirical and theoretical approaches. The importance of interdisciplinary discussion means that philosophers who would like their theorizing to appeal and be relevant to scientific colleagues must spend an increasing amount of time keeping up with the empirical literature, perhaps even going out to gain firsthand experience of the ordeals of fieldwork. And scientists who have not read technically difficult philosophical papers and books must do so if they are to stay abreast of developments. We hope that this book contributes to the understanding of what can be achieved by direct collaboration between philosophers and scientists.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifOur book has the title it does not only because we want to stress the interdisciplinary nature of the field called cognitive ethology but also because we want to emphasize how essential are comparative inquiries into animals´ minds. Defined briefly, cognitive ethology refers to the comparative, evolutionary, and ecological study of animal thought processes, beliefs, rationality, information processing, and consciousness. Cognitive ethology can trace its beginnings to the writings of Charles Darwin, an anecdotal cognitivist, and some of his contemporaries and disciples. Their approach incorporated appeals to evolutionary theory, interests in mental continuity, concerns with individual and intraspecific variation, interests in the mental worlds of the animals, close associations with natural history, and attempts to learn more about the behavior of animals in conditions that are as close as possible to the environments in which natural selection has occurred or is occurring. When needed, research on captive animals also can inform the comparative study of animal cognition. But cognitive ethologists are resistant to suggestions that field studies of animal cognition are impossible (they are difficult, yes, but certainly not impossible), that they should give up their attempts to study animal minds under natural conditions, and that studies of learning and memory alone are sufficient for a complete understanding of animal cognition. In addition to being concerned with the diverse solutions that living organisms have found to common problems, they emphasize broad taxonomic comparisons and do not focus on a few select representatives of a limited number of taxa.

http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifTypically, philosophers of mind have developed their theories anthropocentrically and have applied those theories only secondarily to questions about animal mentality. We believe a more thoroughly naturalistic approach that begins with a consideration of the evolution and biological continuity of human and nonhuman mentality has the potential to produce a more nearly complete understanding of the nature and the evolution of mind. A basic assumption of our approach is that some organisms--humans, at least--are accurately described as having mental states. In making this assumption we are setting aside the worries of "eliminativists" who argue that all talk of minds is hopelessly confused and should be eliminated from the behavioral sciences. Perhaps the eliminativists are right. But, while we are ready to concede that there is confusion about concepts such as belief and consciousness, we do not yet think that the situation is hopeless. It is our view that the best way to understand mental-state attributions across species boundaries is within the comparative, evolutionary, and interdisciplinary framework provided by cognitive ethology. One goal of this book is to make that framework as explicit as possible. Where there are shortcomings in our account, we hope to convince our readers that the difficulties are tractable within the interdisciplinary approach. Ultimately, cognitive ethology will be viable only if a mentalistic approach to the study of animal behavior is capable of sustaining a viable, empirical research program. A major goal that we have in writing this book is to indicate how such a research program might be sustained.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifAlthough there is a great deal of activity by empirical researchers in the comparative study of animal minds, many research programs are narrowly primatocentric, giving only passing attention to animals other than nonhuman primates. We are not the first to urge a broader taxonomic approach to the study of animal minds. It has, for example, been suggested that, in order to learn more about human social behavior and cognition, it is worthwhile to study social carnivores. These animals may provide excellent models for the evolution of cognitive capacities. Many social carnivores are subject to changing environmental conditions, social and nonsocial, that require individuals to show flexible behavior depending on the social composition of their group and the nature of their food supply (Schaller and Lowther 1969; Tinbergen 1972). These carnivores´ groups are also characterized by complex networks of social relationships and divisions of labor that may change unpredictably. Complex social and environmental conditions also appear to have been operating in the evolution of cognition in birds. Our attempt to broaden cognitive ethology is only a beginning, and some might even find our concentration on birds and mammals to be narrower than they like. For example, a good deal of interesting work is already being done on cephalopods (Mather 1995), and a mature cognitive ethology will have to consider the full range of vertebrates and invertebrates. Thus, we hope to correct the primatocentric trend by encouraging our readers to consider the behavior of many of the other animals with whom we share this planet. A "speciesist" cognitivism will impede progress in this exciting and challenging area of inquiry, and it will preclude the amassing of a database that would allow sufficiently motivated claims about mental continuity and animal minds.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifWe stress the importance of conducting empirical, evolutionary, comparative, and ecological studies of animal minds. (See also Yoerg 1991; Yoerg and Kamil 1991; Shettleworth 1993.) We believe that arguments about evolutionary continuity are as applicable to the study of animal minds and brains as they are to comparative studies of kidneys, stomachs, and hearts. We also stress how important it is for those interested in the study of animal minds to make their ideas tractable to empirical research. Cognitive ethology can raise new questions that may be approached from various levels of analysis. For example, detailed descriptive information about subtle behavior patterns and neuroethological data may inform further studies in animal cognition, and may be useful for explaining data that are already available. Such analyses will not make cognitive ethology superfluous, because behavioral evidence is necessary for the interpretation of anatomical or physiological data in assessments of cognitive abilities.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifWe also hope to show that debates about animal minds and cognition really do not come down to a confrontation between "us" (people who argue that many animals have rich cognitive lives) and "them" (methodological or radical behaviorists who view animals as mere stimulus-response machines). We favor pluralism in all areas. Our view is underscored by the assertion that some animals sometimes need to deal with changing social and nonsocial environments, and the best way for them to do this is to store information when it is available so as to be able to extrapolate from it later (Toates 1995). In other situations, it might be better to respond more mechanically, using time-tested responses that have worked in the past.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifWe come to the study of animal minds with the perspective that many animals have minds and rich cognitive lives. Some researchers who come from the behaviorist side of the fence, including Toates, also remain open to the idea that single-minded appeals to a particular explanatory framework are unpromising. Maintaining that one type of explanation is always better than the other is stifling and, we believe, incorrect. If nothing else, ideological and narrow appeals lead us to devalue animals (and this has serious moral implications--see Rachels 1990; and Bekoff 1994a); much more important, this type of closed-minding thinking can impede the work that is sorely needed if we are to improve our understanding of the behavioral capacities of individuals of many species.

http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifCognitive ethologists and comparative or cognitive psychologists can learn important lessons from one another. On the one hand, cognitive psychologists who specialize in highly controlled experimental procedures can teach something about the importance of experimental design and control to those cognitive ethologists who do not perform such research. On the other hand, those who study humans and other animals under highly controlled and often contrived and impoverished laboratory conditions can broaden their horizons and learn more about the importance of more naturalistic methods: they can be challenged to develop procedures that take into account possible interactions among stimuli within and between modalities in more natural settings.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifWe have chosen the topics that we consider in detail not only to emphasize the need to go beyond primates but also because we want to discuss some behavior patterns that do not typically receive detailed discussion in the comparative literature. In a much longer book we could also have considered bee communication; studies of language in primates, cetaceans, and psittacines; tool use; food caching and recovery;teaching; imitation; and self-recognition. (For ample reviews of these topics see Byrne and Whiten 1988; Cheney and Seyfarth 1990, 1992; Allen and Hauser 1991; Ristau 1991; Griffin 1992; Bekoff and Jamieson 1990a,b, 1996a; Dawkins 1993; Kamil 1987; Byrne 1995; Roitblat and Meyer 1995; Bekoff and Allen 1996; Bekoff 1996; Galef 1996b; Nicol 1996; Vauclair 1996; Cummins and Allen 1997.) Griffin, with his broad-based approach to animal cognition and consciousness, considered numerous topics, some of which do not appear to fall squarely within what we view to be the primary domain of cognitive ethology: the study of behavior patterns in natural (or close-to-natural) settings from an evolutionary and ecological perspective. (Of course, this view does not discount entirely the importance to cognitive ethology of research on captive animals.) With respect to ape language, for example, only future research will tell if the behavior of the few captive individuals who have been intensively studied is related to the behavior of wild members of the same species (see e.g. Savage-Rumbaugh et al. 1996), or if the data demonstrating behavioral plasticity and behavioral potential in captive animals are more significant. For similar reasons we have had little to say about the studies in which mirrors have been used to study self-recognition.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifWe have chosen to focus on social play and on antipredatory (vigilance) behavior for a number of reasons. First, it seems to us that these are important areas because there are many points of contact with philosophical discussions of intentionality and representation. Second, we want to discuss areas in which there is a good database but one that needs to be filled out by additional comparative field studies. A return to basics is needed, for many studies have been conducted using simplistic and misleading presuppositions. So, for example, in our discussions of social play and antipredator behavior, we want to learn in detail about what the animals are doing and also to compare different sorts of explanations (e.g., those that appeal to intentionality and representation versus those that appeal to stimulus-response contingencies). In regard to both social play and vigilance, we will argue that noncognitive rule-of-thumb explanations (e.g., "Play this way if this happens or if this happened" and "Play that way if that happens or if that happened," or "Scan this way if there are this number of birds in this geometric array" and "Scan that way if there are that number of birds in that geometric array") are cumbersome and do not seem to account for the data and the flexibility in animals´ behavior as well or as simply as explanations that appeal to cognitive capacities of the animals under study. Of course, more research is needed in these and other areas.

http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifMethodology must also be given serious attention, for it is highly unlikely that the same methods can be used to study cognition and theories of mind in fishes, birds, carnivores, and nonhuman primates. There is a need to develop and implement species-fair tests that tap the sensory and motor worlds of organisms belonging to different taxa. Furthermore, individual differences must be taken seriously. Sweeping generalizations at the species level of explanation can be misleading, and they are often based on studies of a very few individuals or on small data sets. It is important to know as much as possible about the sensory world of the animals whose behavior one is studying. Experimenters should not ask animals to do things that they are unable to do because they are insensitive to the experimental stimuli or unmotivated by them. The relationships between normal ecological conditions and differences between the capabilities of animals to acquire, process, and respond to information are in the domain of a growing field called "sensory ecology." Many good ethologists begin by attempting to develop an awareness of the senses that the animals use singly or in combination with one another. It is highly unlikely that individuals of any other species sense the world in the same way we do, and it is unlikely that even members of the same species sense the world identically all the time. It is important to remain alert to the possibility of individual variation.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifWe begin chapter 1 with a difficult question: How widely are mental phenomena distributed in nature? We also stress the importance of a seriously motivated interdisciplinary approach to this question, and as part of our attempt to argue convincingly for this view we discuss intentionality and consciousness and how interdisciplinary and naturalistic approaches to these topics will help us to make progress. Different ideas about philosophical naturalism and about how to naturalize cognitive ethology are presented. The project of studying animal minds should be broadly naturalistic, although there are various formulations of naturalism that might prove satisfactory and deserve independent investigation. We see Darwinian continuity as one plausible route to a naturalistic theory of mental phenomena and ethology, and cognitive ethology as essential to the pursuit of this route. (We recognize our debts to Darwin and Griffin here and elsewhere.) Our project, then, is to explore how evolutionary accounts of mental phenomena can inform and be informed by philosophical accounts. The current philosophical literature on mental phenomena is dominated by discussions of two major aspects of mentality: intentionality (in Franz Brentano´s sense) and consciousness (in who knows what sense!). The common strategy of treating these phenomena as independent is not unanimously applauded. Throughout this book, we shall be concerned with the benefits and risks of a divide-and-conquer strategy. We shall come out on the side of careful division.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifIt is important to know about some of the historical underpinnings of cognitive ethology. In chapter 2 we briefly consider the historical roots of classical and cognitive ethology and how these two fields may be related. We discuss Darwin´s anecdotal cognitivism and the importance of his ideas about mental continuity between humans and other animals. We then discuss various forms of behaviorism, the rise of classical ethology, and Griffin´s emphasis on consciousness and the versatility of behavior. We conclude that cognitive ethology does not represent a major departure from the practices of classical ethologists such as Konrad Lorenz and Niko Tinbergen, but that the explanatory constructs provided by the application of cognitive science to ethology are conceptually richer than Lorenzian constructs such as "action-specific energy" and "drive." Careful observation, description, interpretation, experimentation, and explanation form the raw material for just about all analyses of behavior, regardless of one´s position on matters of mind, and advances in the philosophical analysis of cognitive concepts provide good prospects for empirical investigation of the applicability of these concepts to animal behavior.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifIn chapter 3 we ask "What is behavior?" We discuss some general but very important methodological topics, including the difference between actions and other movements (that is, between what an animal does and what happens to it) and how behavior patterns are categorized. We also consider the natures of various types and levels of description (for example, acontextual description with reference to muscular contractions and description with reference to function or consequence), and we come down on the side of pluralism. Descriptions can come in many different flavors - none is always correct and none is always incorrect. Rather, the questions being asked (and perhaps the animals being studied) drive the selection of the type of description (and other methods) that should be used.

http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifA balanced view of cognitive ethology requires consideration of critics´ points of view. We attempt to give serious attention to various critics´ challenges in chapter 4, and also in other chapters as the need arises. Criticisms of cognitive ethology come in many forms but usually center on the notion that nonhuman animals do not have minds; on the idea that (many, most, all) animals are not conscious, or that so little of their behavior is conscious (no matter how broadly defined) that it is a waste of time to study animal consciousness; on the inaccessibility to rigorous study of animal mental states (they are private) and whatever (if anything) might be contained in them; on the assumption that nonhuman animals do not have any beliefs because human language is incapable of expressing anything other than the contents of human beliefs; on the belief that there is too much human subjectivity about animal subjectivity; on the rigor with which data are collected; on the lack of large databases (anecdotes are far too prevalent); on the nature of explanations that rely too heavily on theoretical constructs (e.g., minds and mental states) that are regarded as anthropomorphic, folk-psychological, and merely instrumentalistic; and on the reliance on behavior to the exclusion of neurological or physiological explanations of behavior.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifMuch of the criticism of cognitive ethology comes from those who ignore its successes, those who dismiss it in principle because of strong and radical behavioristic leanings, or those who do not always appreciate some of the basic philosophical principles that inform it. The more mechanistic approaches to the study of animal cognition are not without their own faults. Kamil (1987), a comparative psychologist himself, faults many of his colleagues for disregarding external validity (i.e., how relevant a study is to the natural existence of the animals under study) and for paying too much attention to internal validity (i.e., the logical structure of the experiments being performed).
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifIn our response to critics, we introduce the notions of stimulus-bound behaviors (i.e., behavior patterns that occur almost invariably in response to some stimulus, with external stimuli predominating over internal factors) and stimulus-free behaviors (where internal factors predominate over external stimuli). There are different ways of conceiving these internal factors, ranging from interoceptive phenomena to representational accounts of mental states. Here interdisciplinary input is necessary, and Jerry Fodor shakes hands with Niko Tinbergen. For much of the twentieth century, psychology, especially comparative psychology, was on a behavioristic track that explicitly denied the possibility of a science of animal mind. We argue that this halving of psychology depends on unsound arguments about the privacy of mental phenomena and on unsound views about the relationship between observation and theory. The appearance of the adequacy of behavioristic explanations to account for any observed behavior may be an artifact of the way in which comparative psychologists identify behaviors to be explained. When the full complexity of the behaviors is considered, behavioristic explanations can seem rather less straightforward than cognitive or mentalistic ones.

http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifOther challenges to cognitive ethology center on the use of folk-psychological explanations--appeals to animals´ desires and beliefs. In chapter 5 we consider what folk psychology is, consciousness and content, the semantic properties of mental states, and evolutionary explanations of content. We discuss the possibility of traveling smoothly from folk psychology to science and transforming folk psychology into something respectable. We also consider serious criticisms of the notion of belief, concluding that they do not threaten the enterprise of cognitive ethology--that intentional explanations are alive and well and can be used to explain behavior. We argue that a notion of content is essential to the explanatory project of cognitive ethology in that it provides a level of abstraction that is important for comparative accounts of behavior. A common objection to the use of mentalistic terms to explain animal behavior involves both a mistaken understanding of what such terms are best at explaining and an overoptimistic assessment of the scope of nonmentalistic explanations of behavior. We also argue that there are fewer grounds for pessimism about the precise specification of the content of animal beliefs than critics have supposed. The fact that the conceptual schemes of nonhuman animals do not exactly correspond to classifications that are of anthropocentric interest does not mean that more precise specification of content is impossible for the cognitive states of animals.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifOur first case study, presented in chapter 6, concerns social play behavior, especially in canids (members of the dog family). Darwin thought that playful behavior indicated pleasure, and many observers would agree that animals play because it is fun for them to do so. It also is fun to watch animals at play! This aside, there is much of directly cognitive interest in the study of play, including the requirement to communicate intentions about play and the possibilities that the study of play may afford for the development of understanding the context in which various actions may occur in order to distinguish playful actions from their nonplayful counterparts.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifIn addition to the fact that social play exemplifies many of the theoretical issues faced by cognitive ethologists and philosophers, empirical research on social play has benefited and will benefit further from a cognitive approach, because social play involves communication, intention, role playing, turn taking, and cooperation. Furthermore, social play occurs in a wide range of species and thus affords a good opportunity for a comparative investigation of cognitive abilities. Finally, our choice of social play is in keeping with our major goal of discussing behavior patterns--tractable, evolved behavioral phenotypes--that lend themselves to detailed empirical study. Because the social play of canids and other animals involves the use of behavior patterns from other contexts, such as predation, aggression, and reproduction, it is important that when the same patterns are used in play they are not misinterpreted. Thus, in this chapter we concentrate on how individuals communicate that they want to play with others, rather than to eat, fight, or mate with them.

http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifOur second case, study presented in chapter 7, centers on antipredator behavior, mainly in birds--how individuals scan their social and nonsocial surroundings looking for predators or looking at who is nearby and what they are doing. Many of our observations about social play as a cognitive domain also apply to the study of vigilance. However, perhaps even better than play, the vigilance behavior of animals lends itself to broad taxonomic comparisons and is amenable to neurobiological studies and to studies of perceptual abilities. Many vertebrates and invertebrates show minute-by-minute, daily, and seasonal changes in their vigilance behavior. In many cases, the causes of these changes, which are not amenable to simple, single-factor explanations, seem amenable to cognitive analysis. Studying vigilance could allow cognitive ethologists to break away from the tendency to focus on a few select representatives of a few taxa. In short, vigilance studies might allow cognitive ethologists to escape the primatocentrism that plagues much of comparative psychology, and also might make possible real comparative studies of a variety of taxonomic groups. In chapter 7 we use a study of western evening grosbeaks to illustrate the application of cognitive approaches to vigilance behavior. This study concerned the sorts of information accessible to these birds as they feed in small to medium-size groups and scan for potential predators and the expectations they might have about the behavior of other flock members.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifIn chapter 8 we turn to the topic of consciousness. Although some of the classical ethologists (especially Tinbergen) were skeptical or hostile toward the idea that animals´ subjective experiences could be investigated rigorously (Burkhardt 1997; van den Bos 1997), Griffin placed the topic at the top of his agenda for cognitive ethology. We wait so long to get to this important but highly controversial and muddled area because we wish to illustrate that there is much of interest in cognitive ethology that can be pursued even in the absence of a completely satisfying account of consciousness. We try in chapter 8 to reorient the debate about animal consciousness away from Thomas Nagel´s famous question "What is it like to be a bat?" and back toward the question of which creatures possess consciousness. We discuss the lack of a need to provide a stipulative definition of consciousness; we consider qualia, sensations, and information; and we stress the importance of learning about how animals detect misinformation. We hope to convince our readers that some questions about animal consciousness may be empirically tractable, even if others seem at present intractable.

http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifWithout a doubt, the difficulty of understanding consciousness is the single biggest bludgeon used to bash cognitive ethology. We think that to focus on this difficulty is to be very unfair to cognitive ethologists, for many interesting questions about the evolution of mentality can be pursued in the absence of solutions to all the problems of consciousness. Many philosophers have focused on how one can know what it is like for another organism to be in a particular conscious state. We argue that the more fundamental epistemological question concerns which organisms have conscious states, not what it is like to be those organisms. For many philosophers, however, the epistemological problems of consciousness pale in comparison to the ontological problem of saying just what consciousness is. We do not think that the project now facing cognitive ethologists and comparative psychologists requires us to say anything explicit about the ontological problem of consciousness. For present purposes it is enough to point to cognitive and behavioral capacities that exhibit some of the characteristics associated with consciousness and to target those for further empirical investigation and philosophical analysis. Only this kind of interdisciplinary research will tell whether those capacities are the ones to which we should be pointing.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifIn chapter 9 we attempt to provide a synthesis of philosophical, psychological, and ethological approaches to the study of animal minds. We directly head off the attempt by Cecilia Heyes and Anthony Dickinson (1990, 1995)--severe but cogent critics of cognitive ethology--to argue that only in the laboratory is it possible to rigorously test hypotheses about the intentionality of animal behavior. Heyes and Dickinson´s arguments are flawed, we believe, by an excessively narrow dedication to Daniel Dennett´s (1983, 1987) conception of intentionality and by a lack of attention to the natural history of their laboratory subjects.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifIn summary, we argue that the following should figure prominently in cognitive ethological studies: remaining open to the possibility of surprising findings about animals´ cognitive abilities
concentrating on comparative, evolutionary, and ecological questions
sampling many different species, including domesticated animals--going beyond primates, and avoiding talk of "lower" and "higher" animals (or at least laying out explicit criteria for using these slippery and value-laden terms)
naturalizing the methods of study by taking the animals´ points of view (communicating with them on their terms) and studying them in conditions that are close to the conditions in which they typically live
trying to understand how cognitive skills used by captive animals may function in more natural settings
studying individual differences
using all sorts of data, ranging from anecdotes to large data sets
appealing to a variety of types of explanation in the search for the best explanations of the data under scrutiny. Cognitive ethology need not model itself on other fields of science, such as physics or neurobiology, in order to gain credibility. Envy of the "hard" sciences is what led to the neglect of animal and human minds in the early part of the twentieth century.
http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/sp.gifAll in all, we hope that our readers will come away from this book recognizing that the comparative and evolutionary study of animal minds is a most exciting and challenging interdisciplinary field of inquiry that is worthy of respect from those who think it a soft science: it is not. Interdisciplinary research is difficult, and it becomes even more so when impassable boundaries are established between academic disciplines (Bekoff 1994b; van Valen 1996). Our hope is that traditional academic territories will be abandoned in areas where friendly overlap is essential to the advancement of knowledge; cognitive ethology is such an area. We recognize that not everyone will be satisfied. Some may wish to see more experimentation and less theorizing. We agree that more experimentation is desirable, but a solid theoretical approach is equally important. Most of all, we hope that our critics will come forth and mount serious challenges to what we have written, for in this way we can continue to develop and to refine ideas that will make the worlds of other animals more understandable to us.

http://grimpeur.tamu.edu/~colin/SpeciesofMind/ (http://grimpeur.tamu.edu/%7Ecolin/SpeciesofMind/)