Phylogenetic Approach to Object Manipulation in Human and Ape Infants

Abstract

Object manipulation in primates is discussed with regard to the phylogenetic evolution of intelligence. Comparative data are reported on prehension schemes and levels of complexity in object manipulation by three primate species: a human infant, a pigmy chimpanzee, and a common chimpanzee. Characteristics of object manipulation in apes (e.g., exploratory mouthing without removal of objects from background) are compared with the typical manipulations performed by the human infant involving discrete and movable objects. It is hypothesized that the developmental retardations occurring in human ontogeny (e.g., in locomotion) bring about a specific mode of contact with the external world, namely the use of intermediaries to control objects, whereas apes use body movements to achieve a more direct contact with objects. The implications of a prolonged immaturity in primates and especially in humans are discussed with reference to the emergence of different prehensive, manipulatory, and communicative patterns in human and ape infants.