In this paper I consider whether traditional behaviors of animals, like traditions of humans, are transmitted by imitation learning. Review of the literature on problem solving by captive primates, and detailed consideration of two widely cited instances of purported learning by imitation and of culture in free-living primates (sweet-potato washing by Japanese macaques and termite fishing by chimpanzees), suggests that nonhuman primates do not learn to solve problems by imitation. It may, therefore, be misleading to treat animal traditions and human (...) culture as homologous (rather than analogous) and to refer to animal traditions as cultural. (shrink)

As the cognitive revolution was slow to come to the study of animal behavior, the vast majority of what we know about primate cognition has been discovered in the last 30 years. Building on the recognition that the physical and social worlds of humans and their living primate relatives pose many of the same evolutionary challenges, programs of research have established that the most basic cognitive skills and mental representations that humans use to navigate those worlds are already possessed by (...) other primates. There may be differences between humans and other primates, however, in more complex cognitive skills, such as reasoning about relations, causality, time, and other minds. Of special importance, the human primate seems to possess a species-unique set of adaptations for “cultural intelligence,” which are broad reaching in their effects on human cognition. (shrink)

Since the BBS article in which Premack and Woodruff (1978) asked “Does the chimpanzee have a theory of mind?,” it has been repeatedly claimed that there is observational and experimental evidence that apes have mental state concepts, such as “want” and “know.” Unlike research on the development of theory of mind in childhood, however, no substantial progress has been made through this work with nonhuman primates. A survey of empirical studies of imitation, self-recognition, social relationships, deception, role-taking, and perspective-taking suggests (...) that in every case where nonhuman primate behavior has been interpreted as a sign of theory of mind, it could instead have occurred by chance or as a product of nonmentalistic processes such as associative learning or inferences based on nonmental categories. Arguments to the effect that, in spite of this, the theory of mind hypothesis should be accepted because it is more parsimonious than alternatives or because it is supported by convergent evidence are not compelling. Such arguments are based on unsupportable assumptions about the role of parsimony in science and either ignore the requirement that convergent evidence proceed from independent assumptions, or fail to show that it supports the theory of mind hypothesis over nonmentalist alternatives. Progress in research on theory of mind requires experimental procedures that can distinguish the theory of mind hypothesis from nonmentalist alternatives. A procedure that may have this potential is proposed. It uses conditional discrimination training and transfer tests to determine whether chimpanzees have the concept “see.” Commentators are invited to identify flaws in the procedure and to suggest alternatives. Key Words: apes; associative learning; concepts; convergence; deception; evolution of intelligence; folk psychology; imitation; mental state attribution; monkeys; parsimony; perspective-taking; primates; role-taking; self-recognition; social cognition; social intelligence; theory of mind. (shrink)

If culture is defined as variation acquired and maintained by social learning, then culture is common in nature. However, cumulative cultural evolution resulting in behaviors that no individual could invent on their own is limited to humans, song birds, and perhaps chimpanzees. Circumstantial evidence suggests that cumulative cultural evolution requires the capacity for observational learning. Here, we analyze two models the evolution of psychological capacities that allow cumulative cultural evolution. Both models suggest that the conditions which allow the evolution of (...) such capacities when rare are much more stringent than the conditions which allow the maintenance of the capacities when common. This result follows from the fact that the assumed benefit of the capacities, cumulative cultural adaptation, cannot occur when the capacities are rare. These results suggest why such capacities may be rare in nature. (shrink)

Most putative cases of teaching in nonhuman animals involve parent-offspring interactions. The interpretation of these cases, particularly with regard to the cognitive processes involved, is controversial. Qualitative and quantitative observations made in nonhuman primates suggest that, in some species, mothers encourage their infants’ independent locomotion and that encouragement can be considered a form of instruction. In macaques, experience in raising previous offspring accounts in part for variability between mothers in propensity to encourage infant motor skills. Parsimony suggests that the cognitive (...) mechanisms underlying maternal encouragement of infant locomotion in primates as well as some other putative cases of animal teaching may involve first-order intentionality (i.e., goal-directed behavior) and not higher cognitive processes such as attribution of knowledge/ignorance or perspective-taking. Encouragement of infant independent locomotion early in life may have benefits to mothers later on, in terms of reduction of costs of infant carrying, earlier infant weaning, and increased probability of reproduction in the mating season. The elementary forms of teaching observed in nonhuman primates may have played an important role in the origin and evolution of human culture. (shrink)

In this book, field and laboratory researchers show that the Great Apes are capable of thinking at symbolic levels, traditionally considered uniquely human.

Byrne & Russon propose that priming can account for the imitation of simple actions, but they fail to explain how the behavior of another can prime the observer's own behavior. They also propose that imitation of complex skills requires a sequence of acts tied together by a program, but they fail to rule out the role of trial-and-error learning and perceptual/motivational mechanisms in such task acquisition.

Byrne & Russon rightly draw attention to complex and neglected aspects of ape imitation. However, program-level imitation as a single, absolute category may mislead us in understanding abstractions involved in imitation. Designing the right experiments will offer clarity. One recent experiment has shown imitation of sequential structure: What is needed to test other components of what the authors propose?

Great apes show behavioural evidence for secondary representation similar to that of children of about two years of age. However, there is no convincing evidence for metarepresentation in apes. A good evolutionary interpretation should be parsimonious and must bring developmental and comparative data in accord. I propose a model based on the work of Perner (1991) and close by pointing out a logical flaw in Heyes’ second proposed experiment.

We commend Byrne & Russon for their effort to expand and clarify the concept of imitation by addressing the various levels of behavior organization at which it could occur. We are concerned, however, first about the ambiguity with which these levels are defined and second about whether there is any particular need for comparative cognition to keep focusing on imitation as an important intellectual faculty. We recommend stricter definitions of hierarchical behavioral levels that will lend themselves to operational definitions and (...) continued study of how animal subjects organize their goal-directed behavior as opposed to whether it is or is not imitation. (shrink)

Byrne & Russon use novelty as the primary requirement for providing evidence of true imitation in animals. There are three reasons to object to this. First, experiential learning cannot always be completely excluded as an alternative explanation of the observed behavior. Second, the imitator's manipulations performed during ontogeny cannot be known in full detail. Finally, there is at present only a weak understanding of how novel forms emerge. Data from our own recent experiments will be used to emphasize the need (...) for a tighter methodology in imitation experiments. (shrink)

Byrne & Russon's proposal that stimulus enhancement, emulation, and response facilitation should be lumped together as priming effects conceals important questions about nonimitative social learning, fails to forge a useful link between the social learning and cognitive psychological literatures, and leaves unexplained the most interesting feature of phenomena ascribed to.

To explain social learning without invoking the cognitively complex concept of imitation, many learning mechanisms have been proposed. Borrowing an idea used routinely in cognitive psychology, we argue that most of these alternatives can be subsumed under a single process, priming, in which input increases the activation of stored internal representations. Imitation itself has generally been seen as a This has diverted much research towards the all-or-none question of whether an animal can imitate, with disappointingly inconclusive results. In the great (...) apes, however, voluntary, learned behaviour is organized hierarchically. This means that imitation can occur at various levels, of which we single out two clearly distinct ones: the a rather detailed and linear specification of sequential acts, and the a broader description of subroutine structure and the hierarchical layout of a behavioural Program level imitation is a high-level, constructive mechanism, adapted for the efficient learning of complex skills and thus not evident in the simple manipulations used to test for imitation in the laboratory. As examples, we describe the food-preparation techniques of wild mountain gorillas and the imitative behaviour of orangutans undergoing to the wild. Representing and manipulating relations between objects seems to be one basic building block in their hierarchical programs. There is evidence that great apes suffer from a stricter capacity limit than humans in the hierarchical depth of planning. We re-interpret some chimpanzee behaviour previously described as and suggest that all great apes may be able to imitate at the program level. Action level imitation is seldom observed in great ape skill learning, and may have a largely social role, even in humans. (shrink)

In this enlightening exploration of our nearest primate relatives, Michael Tomasello and Josep Call address the current state of our knowledge about the cognitive skills of non-human primates and integrate empirical findings from the beginning of the century to the present.

"Intelligence" has long been considered to be a feature unique to human beings, giving us the capacity to imagine, to think, to deceive, to make complex connections between cause and effect, to devise elaborate stategies for solving problems. However, like all our other features, intelligence is a product of evolutionary change. Until recently, it was difficult to obtain evidence of this process from the frail testimony of a few bones and stone tools. It has become clear in the last 15 (...) years that the origins of human intelligence can be investigated by the comparative study of primates, our closest non-human relatives, giving strong impetus to the case for an "evolutionary psychology", the scientific study of the mind. (shrink)