A report of behavioral lateralization in an infant orang-utan (Pongo pygmaeus)

The limb used to perform seven common activities was recorded during weekly observations of an infant orang-utan. For five of these behaviors, preferences were found that remained consistent in their direction, although there were week to week fluctuations in magnitude. Most notably, a right hand preference was found for nonfood reaching and a right hindlimb preference appeared for initiating locomotion. Although initially, food reaching was predominantly with the right hand, a shift toward preferential left hand use occurred during the final weeks of the study. Additionally, a left hand preference appeared when the infant touched either its body or head.