The Development of Spontaneous Gestures in Zoo-living Gorillas and Sign-taught Gorillas 101

Abstract: We analyze the developmental sequence in which different types of representa-tion appear in untaught signs in the repertoire of Koko, a signing gorilla, and in the ges-tures developed by zoo-living gorillas at different ages. There is a progression in all the subjects from pure action to iconic representation of action. The signing gorilla, in addi-tion, depicts objects. This is done through hand shape, miming of an action related to the use of an object, or by tracing the outline of an object. The various spatial mediums (i.e., on the body versus in open space) in which signs are performed assist in understanding of the cognitive processes supporting ape representation and communication. The progres-sion from ape “action mapping ” to the level of representation found in human language is viewed as a series of stages that follow logically upon each other in a continuum of de-velopment, both in individuals and in possibly in the history of the hominoid family