The Evolution of Handedness in Primates

Abstract

It is almost universally believed that non-human primates do not have population-level hand preference asymmetries. The most influential proponent of this view has been J. M. Warren who has stated it in several recent reviews. (Warren, 1977 a, b; Warren and Nonneman, 1976; Warren, 1980). However this conclusion is probably wrong. There is, in fact, a good deal of evidence for population-level hand preferences in non-human primates. At least a dozen statistically significant asymmetries have been reported, and some of these have been in the literature for many years. When examined closely these results reveal a pattern. The earliest primates, the prosimians, show a left hand preference in reaching for and prehending food. This is also observable in monkeys. But in monkeys there is also evidence for development of a right hand preference for practiced stereotyped acts involving more than simple reaching, in laboratory situations; and there is strong evidence in one study (Beck and Barton, 1972) of a right hand preference for complex manipulative acts. In this study, the left hand reaching preference and the right hand manipulative preference were observed in the same animals. The left hand reaching preference may not be present in apes. There is some evidence for a right hand reaching preference in males. And there is strong evidence in 4 species of apes for a right limb (hand and foot) preference in the initiation of locomotion. In humans of course the left hand preference is absent under ordinary circumstances, but right hand and foot preferences are dominant in the population.KeywordsNonhuman PrimateHand PreferenceJapanese MacaqueJapanese MonkeyPectoralis Major MuscleThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.