R. Allen Gardner

COMPARATIVE PSYCHOLOGY AND LANGUAGE ACQUISITION

A science of psychology must assume that behavior is lawful. We recognize diversity, but we assume that both similarity and difference are products of the same fundamental laws that combine and recombine in unique ways to yield the rich diversity of behavior that we observe between and within species. The proper analysis of behavior is not in terms of simpler behavior and more complex behavior or in terms of simpler organisms and more complex organisms, but rather in terms of general functions such as perception and learning that are found in all forms of behavior. We avoid the invention of new laws of behavior for each newly discovered level of complexity in favor of the formulation of more powerful generalizations.

Two-Way Communication with an Infant Chimpanzee

Publisher Summary This chapter discusses two-way communication with an infant chimpanzee. Language is the most important result of the evolutionary developments that distinguish human beings from other species. It is difficult to study language on the same objective terms as other types of behavior. The study of language has come to lose much of the mystique that it once had. If an animal, such as a chimpanzee (Pan troglodytes) is capable of developing a system of two-way communication of its own, the place to observe this can be in well-established wild bands. In choosing an appropriate medium for communication with a chimpanzee, one must first consider carefully why a medium based on vocalization cannot be appropriate. A chimpanzee can never communicate by speech because of anatomical defects in its vocal apparatus. Many human tools and mechanical devices are designed for the human hand, yet chimpanzees can learn to use these with great skill. To some extent, chimpanzees should be able to use a medium of communication designed for human vocal anatomy. Intelligible speech can be produced by human beings with the pathological defects of the vocal apparatus, and there are human languages that substitute whistles or clicks for speech.

A vocabulary test for chimpanzees ( Pan troglodytes ).

Chimpanzees can communicate in American Sign Language (ASL) to independent human observers whose only source of information is the ASL signs of the chimpanzees. A vocabulary test was presented to 4 cross-fostered chimpanzees (4-6 years old). Thirty-five-millimeter color slides were projected on a screen that could be seen by the chimpanzee subject but not by the human observers. There were two observers: O1 was the questioner in the testing room with the subject; O2 was in a different room. Neither observer could see the other, or the responses of the other observer. O1 and O2 agreed in their readings of both correct and incorrect signs, and most of the signs were the correct ASL names of the slides. In order to show that the chimpanzees were naming natural language categories--that the sign DOG could refer to any dog, FLOWER to any flower, SHOE to any shoe--each test trial was a first trial in that test slides were presented only once. Analysis of errors showed that two aspects of the signs, gestural form and conceptual category, governed the distribution of errors.

Object permanence in child and chimpanzee

In a repeated-measures design, two infant chimpanzees and three human infants were tested in like manner using the Uzgiris and Hunt (1975) stepwise assessment instrument for the development of object permanence in human infants. Comparisons between chimpanzee and human subjects showed similarities in the number of steps achieved, in the order and rate of achieving the steps, and in the detailed characteristics of searching behavior. These results suggest that the course of development of the concept of object permanence, as described by Piaget, is a very general one.

Feedforward versus feedbackward: An ethological alternative to the law of effect

The view that learning is governed by positive and negative consequences has dominated theory and application throughout this century. In some systems stimulus-response connections are stamped in or stamped out by the consequences of action, in others, cognitive expectancies are formed by experience with past consequences. The evidence from early experiments with rats and pigeons and the feedback principles of early servomechanisms seemed to offer both hard evidence and a plausible model for the law of effect in either its behaviorist or its cognitive form. A large body of evidence demonstrates that the results of operant conditioning appear regardless of and often in spite of response-contingent consequences. Experiments designed to measure a residual effect of consequences exhibit an inevitable ex post facto error that vitiates all possible versions of this experimental design. Experiments designed to measure the effect of predictive contingency in Pavlovian conditioning exhibit a corresponding error. There appears to be a fundamental logical defect in all contingency models of the learning process. Meanwhile, modern developments in ethology and computer science provide a unified feedforward model of the learning of adaptive and maladaptive behavior under both laboratory and field conditions. Because the feedforward model is more parsimonious, it is also more compatible with Darwinian principles of biological economy. Research on teaching new and challenging tasks to freeliving, well-fed subjects such as children and cross-fostered chimpanzees illustrates the wide applicability and practical effectiveness of feedforward.

Discovering and Understanding the Meaning of Primate Signals

This volume, edited by a philosopher and an anthropologist, is a collection of essays on the philosophical implications of laboratory and field research. While neither the best nor the worst of the genre, it is a collection that offers a representative sample of traditional themes. As practicing scientists who view the implications of behavioural research from a somewhat different perspective we offer this critical review.

How cross-fostered chimpanzees ( Pan troglodytes ) initiate and maintain conversations.

This study systematically sampled typical attention-getting sounds and sign language conversations between each of 4 originally cross-fostered chimpanzees (Pan troglodytes), still living freely, but now in a laboratory setting, and a familiar human interlocutor. Videotape records showed that when they encountered a human interlocutor sitting alone at his desk with his back turned to them, the cross-fosterlings either left the scene or made attention-getting sounds. The only signs they made to the interlocutors back were noisy signs. When the human turned and faced them, the chimpanzees promptly signed to him (98% of the time) and rarely made any sounds during the ensuing signed conversations. Under systematic experimental conditions, the signed responses of the chimpanzees were appropriate to the conversational styles of the human interlocutor, confirming daily field observations.

The Ethological Roots of Culture

Studying the ethological roots of culture R.A. Gardner, B.T. Gardner. Part I: Field Studies. Evidence of structure in macaque communication A. Zeller. The central-peripheral structure of the Tanaxpillo colony of stumptail macaques D.R. Rasmussen, E. Riordan, M. Farrington, E. Kelly, J. Nachman, S. Fernandez, A. Churchill. Cultural implications of differences between populations of free-ranging chimpanzees in Africa W.C. McGrew. Precultural behaviour of Japanese macaques: Longitudinal studies of the Koshima troops K. Watanabe. Bird song learning: a model of cultural transmission? P.J.B. Slater, J.M. Williams. Swarm intelligence and the emergence of cultural swarm patterns G. Theraulaz, J.-L. Deneubourg. Part II: Laboratory Studies. Mother-pup transmission of a feeding technique in the golden hamster E. Prato Previde, M.D. Poli. A study of social, genetic, and environmental determinants of cultural transmission in the house mouse P. Valsecchi, I. Bosellini, D. Mainardi, M. Mainardi. Can chimpanzees use tools by observational learning? D. Paquette. Social transmission of stimulus recognition by birds, fish and molluscs M.D. Suboski. Part III: Cross-Fostered Chimpanzees. Ethological roots of language R.A. Gardner, B.T. Gardner. Development of phrases in the utterances of children and cross-fostered chimpanzees B.T. Gardner, R.A. Gardner. Transmission of human gestural language in a chimpanzee mother-infant relationship R.S. Fouts. The use of remote video recordings to study the use of American Sign Language by chimpanzees when no humans are present D.H. Fouts. Part IV: Infant Development. Is there prenatal culture? M.-C. Busnel. The earliness and complexity of the interaction skills and social behaviours of the child with its peers H. Montagner, B. Epoulet, G. Gauffier, R. Goulevitch, V. Huvert-Ruiz, N. Ramel, B. Wiaux, A. Restoin, M. Taule. Learning by instincts, developmental transitions and the roots of culture in infancy F.X. Plooij, H.H.C. Van de Rijt-Plooij. Part V: Ethnographic and Historical Patterns. An ethological perspective on human handedness L.F. Marchant, W.C. McGrew. Culture and olfactory communication M. Kirk-Smith. Cultural evolution in man of postures, gestures, and unverbalized social relations C. Russell, W.M.S. Russell. Part VI: Paleoanthropological Patterns. Evolution of human culture: a composite pattern F. Giusti. Culture and its biological origins: a view from ethology, epigenesis and design V. Geist. Causes of our complete dependence on culture P. Slurink.

Interactive use of sign language by cross-fostered chimpanzees (Pan troglodytes).

Cross-fostered as infants in Reno, Nevada, chimpanzees (Pan troglodytes) Washoe, Moja, Tatu, and Dar freely converse in signs of American Sign Language with each other as well as with humans in Ellensburg, Washington. In this experiment, a human interlocutor waited for a chimpanzee to initiate conversations with her and then responded with 1 of 4 types of probes: general requests for more information, on-topic questions, off-topic questions, or negative statements. The responses of the chimpanzees to the probes depended on the type of probe and the particular signs in the probes. They reiterated, adjusted, and shifted the signs in their utterances in conversationally appropriate rejoinders. Their reactions to and interactions with a conversational partner resembled patterns of conversation found in similar studies of human children.

Animal cognition meets evo-devo

Sound comparative psychology and modern evolutionary and developmental biology (often called evo-devo) emphasize powerful effects of developmental conditions on the expression of genetic endowment. Both demand that evolutionary theorists recognize these effects. Instead, Tomasello et al. compares studies of normal human children with studies of chimpanzees reared and maintained in cognitively deprived conditions, while ignoring studies of chimpanzees in cognitively appropriate environments.