Abstract

This article reviews experimental and observational research on laterality of manual functions in nonhuman primates and the theoretical models proposed to explain the phylogenetic origins of human handedness. The results of these studies show that population-level hand asymmetries are present in nonhuman primates for a variety of behavioral activities, although these asymmetries can be influenced by several variables, such as the posture adopted by the subjects as well as the manipulative requirements of the tasks. Examination of hand preferences for those activities involving the simultaneous and coordinated use of both hands showed consistent asymmetries, either in the direction and degree of hand preferences, almost in apes. Overall, these findings challenge the long-held belief that laterality in hand use is a uniquely human characteristic.