Introduction: Identifying and Defining Imitation
CECILIA M. HEYES Department of Psychology University College London LondonWC1E 6BT United Kingdom
I mitation has long been regarded as a special kind of social learning, unique in both its psychological complexity and potential to support cultural transmission (e.g., Thorndike, 1898; Washburn, 1908; Piaget, 1962; Boyd & Richerson, 1985; Galef, 1988). Consequently, although imitation may appear to be just one of many types of social learning, it is the principal focus of psychological research on social learning in animals, and, correspondingly, the concern of nearly half of the chapters in this collection.
The dual significance of imitation, its perceived importance not only as a sign of complex psychological processing but also as a means of effecting the nongenetic transmission of information, may have contributed to the problems that have been encountered both in defining imitation conceptually and in identifying it empirically. For at least a century, researchers have been preoccupied with the questions of how the term "imitation" should be applied, which hypothetical class of phenomena it should be understood to name, and how instances of this class can be identified in practice, distinguished empirically from other forms of social learning. These issues may have proved especially intractable in the case of imitation because its dual significance entails that they are addressed by people with a variety of disciplinary backgrounds and theoretical purposes, including ethologists, experimental