INTRODUCTION

This chapter will focus on aspects of great ape gestural communication that have implications for cognition and human language. From an evolutionary perspective, gestures may provide an important link across primate species in communicative systems. As a researcher interested in the development of language in human infants, and its precursors, I will stress similar developments, or their absence, in great apes. These developments will include communicative gestures, symbolic gestures, sign acquisition, and sign combinations.

Gesture has a very broad usage; here it will be restricted to movements of the hand, arm, head, and body with communicative functions. Postural and tactile gestures, as well as facial expressions, although often communicative, are not a focus because their implications for language are unclear. It must be kept in mind, however, that visual communication is a complex, redundant system in which these various components are usually combined (Marler 1965).

I will begin with a brief review of communicative gestures according to their functions and then focus on specific gestures involved in exchange, requests involving cognizance of agency, and pointing, as well as on the degree to which great ape gestures are intentional and inventive. These are the kinds of gestures and their characteristics that are related to the development of language in human infants. I then discuss the extent to which apes display symbolic gestures, both in captivity and in the wild, because such gestures in human infants emerge during the transition to language.