A comparative study of aimed throwing by monkeys and humans

This research examined hand preference and postural characteristics of aime d throwing in capuchin monkeys and humans. We sought to directly compare th e throwing performances of these primates, particularly the extent to which target distance influences hand preference, throwing posture, and throwing accuracy. For both species we found positive correlations between target d istances for throwing accuracy, direction and strength of hand preference, percentage of bipedal vs tripedal throws, and percentage of overarm vs unde rarm throws. Throwing accuracy did not vary as a function of right vs left hand use although for monkeys throwing accuracy was positively associated w ith hand preference strength. We noted a sex difference among humans as mal es threw more accurately than did females. Between-species analysis indicat ed that humans exhibited greater right- vs left-hand use, greater hand pref erence strength, a greater relative percentage of bipedal vs tripedal throw s, and a lower relative percentage of overarm vs underarm throws than did m onkeys. We believe that the capuchin monkey is an informative nonhuman prim ate model of aimed throwing in humans and that research examining the throw ing behavior of capuchins provides insight into the neurological and behavi oral characteristics that underlie coordinated multi-joint movements across the primate order. (C) 2000 Elsevier Science Ltd. All rights reserved.