Handedness in captive gorillas (Gorilla gorilla).

Species-level right handedness is frequently presented as a marker of human uniqueness. Handedness also has implications for the evolution of language and cognition. In this study, we examined handedness in 22 captive gorillas (Gorilla gorilla) across a range of behaviours that were part of their daily routine. Ten individuals showed no preferences for any of the behaviours performed, and the majority of the remaining individuals showed a preference for only one behaviour. These results lend support to the theory that species-level handedness is unique to humans. It is hoped that these results will contribute to investigations into the evolution of handedness, which can ultimately be used to further our understanding of the evolution of human language and cognition.