Genetic and environmental contributions to the expression of handedness in chimpanzees (Pan troglodytes)

Authors

  • W. D. Hopkins,

    Corresponding author
    1. Neuroscience Institute and Language Research Center, Georgia State University, Atlanta, GA, USA
    • Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA, USA
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  • M. J. Adams,

    1. Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
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  • A. Weiss

    1. Scottish Primate Research Group
    2. Department of Psychology, School of Philosophy, Psychology and Language Sciences, The University of Edinburgh, Edinburgh, UK
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Corresponding author: W. D. Hopkins, Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, GA 30322, USA. E-mail: whopkins4@gsu.edu

Abstract

Most humans are right-handed and, like many behavioral traits, there is good evidence that genetic factors play a role in handedness. Many researchers have argued that non-human animal limb or hand preferences are not under genetic control but instead are determined by random, non-genetic factors. We used quantitative genetic analyses to estimate the genetic and environmental contributions to three measures of chimpanzee handedness. Results revealed significant population-level handedness for two of the three measures—the tube task and manual gestures. Furthermore, significant additive genetic effects for the direction and strength of handedness were found for all three measures, with some modulation due to early social rearing experiences. These findings challenge historical and contemporary views of the mechanisms underlying handedness in non-human animals.

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