Visual laterality responses to different emotive stimuli by red-capped mangabeys, Cercocebus torquatus torquatus.

Hemispheric asymmetry in emotional perception has been put forward by different theories as the right hemisphere theory or the valence theory. But no consensus was found about the role played by both hemispheres. So, in order to test the different theories, we investigated preferential use of one eye in red-capped mangabeys, at the individual as well as at the group level.