Capuchin monkeys are playful, inquisitive primates known for their manual dexterity, complex social behavior, and cognitive abilities.
New research now shows that just like humans, they display a fundamental sex difference in the organization of the brain, specifically in the corpus callosum, the region that connects the two cerebral lobes.
A recently published paper by Associate Professor of Psychology and Biology Kimberley A. Phillips (Hiram College), Chet C. Sherwood (George Washington University) and Alayna L. Lilak (Hiram College), reports finding both sex and handedness influences on the relative size of the corpus callosum. The researchers' contribution appears in PLoS ONE, the online, open-access journal of the Public Library of Science. The paper can be read at: http://www.plosone.org/doi/pone.0000792.
In the study, thirteen adult capuchins underwent magnetic resonance imaging of the brain to determine the size of their corpus callosum, which is the major white matter tract connecting the left and right cerebral hemispheres. The monkeys were later given a task to determine hand preference. The authors' results led them to conclude that, as in humans, male capuchins have a smaller relative size of the corpus callosum than females, and right-handed individuals have a smaller relative size of the corpus callosum than left-handed individuals.