Hand preferences for a haptic task in chimpanzees (Pan troglodytes)

We tested the hand preferences of 20 chimpanzees (Pan troglodytes) for a ha ptic task requiring individuals to search for grapes in an opaque bucket fi lled with water. We compared these data to the hand preferences displayed b y the same chimpanzees during reaching and bimanual feeding tasks. The chim panzees displayed no significant hand preference for the reaching or bimanu al feeding tasks, but exhibited a right-hand preference while performing th e haptic task. In contrast, New and Old World monkeys display left-hand pre ferences for similar tasks. We discuss the relevance of these findings for the evolution of handedness in primates.