INTRODUCTION

Most studies of the effects of social interaction on the ontogeny of vocal communication in birds and primates concentrate on the normal course of development of species-specific codes: how birds learn conspecific song, how nonhuman primates develop their natural repertoire of calls, and how human infants develop language. The effects of social interaction, however, are probably even more important during exceptional learning (Pepperberg 1985): learning that is unlikely to occur in the normal course of events. Such learning, defined and described below, has been documented for a number of species, including humans. I have been particularly interested in examining how social interaction can influence a specific type of exceptional learning – the development of interspecies communication between humans and birds. My research on the effects of social interaction on the acquisition of a vocal, English-based code by grey parrots (Psittacus erithacus) clearly demonstrates how social and environmental input1 can engender learning that would not otherwise occur (e.g., Pepperberg 1990a). Interestingly, an analysis of research on ape language also demonstrates how social interaction may be a particularly effective means of teaching nonvocal human-based communication codes to nonhuman primates.

Although characterizing the effects of social and environmental influences on exceptional learning is not a simple task, my work has shown that a conceptual framework, social modelling theory, can be used (a) to characterize how social input influences learning and (b) to delineate the critical features of input necessary for exceptional learning.