title: Left-handedness and longevity in primates.
abstract: In the present research we used the rhesus macaque to model the decline in the incidence of left-handedness that has been noted in the aged human population. We found a significant group-level bias towards use of the left hand among young-adult macaques, and a significant group-level bias towards use of the right hand among aged macaques. The distribution of hand preference across age classes cannot be explained through simple elimination of left-handed subjects in the aged population. Rather, our data are consistent with a maturational view positing increased use of the right hand with increased age. Similar findings across phylogenetically diverse primate taxa suggest that this phenomenon is an evolutionarily ancient trait. Greater use of the left hand in male versus female macaques indicates that sex differences in hand preference are also deeply rooted in our primate origins.
authors.affiliation: Division of Research, LABS of Virginia, Inc., Yemassee, SC 29945, USA.
authors.forename: G C
authors.initials: GC
authors.lastname: Westergaard
authors.forename: I D
authors.initials: ID
authors.lastname: Lussier
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D005075:Biological Evolution; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D008136:Longevity / Q000502:physiology*; D008253:Macaca mulatta / Q000502:physiology*; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology