Hand preference in unimanual and bimanual coordinated tasks in wild western lowland gorillas (Gorilla gorilla gorilla) feeding on African ginger (Zingiberaceae).

This study confirmed that bimanual coordinated tasks are more sensitive in detecting hand preferences in nonhuman primates. In addition to the bimanual nature of the task, the precision grip for processing and the importance of African ginger as a food resource might influence the expression of hand preference. Evidence of a group-level right-hand preference may support the "postural origins theory." Because all wild African great apes feed on the pith of African ginger, comparing this task and its hand preferences can contribute toward a better understanding of the evolution of handedness in Hominidae.