Development of Hand and Paw Preferences and Their Association with Other Patterns of Behaviour and Cognition

Hand preference in non-human primates has been studied extensively with the aim of understanding the evolution of hemispheric asymmetry and hand preferences in humans. However, the focus has been on hand preferences expressed in adulthood, with a surprising lack of studies on hand preferences in infants and changes that occur during the development of other, potentially associated, asymmetries in the brain and behaviour. This paper reports on the development of hand preference for grasping food and taking it to the mouth in common marmosets. It considers the de-velopment of other types of behaviour, such as head cocking and anogenital licking, that parallel and might influence the development of hand preferences during the first months of life. It then discusses behavioural differences between left- and right-handed adult marmosets, including response to novel stimuli, social behaviour and cognitive bias. The need to study the development of hand preferences together with the development of these other expressions of cognitive function is highlighted. The question to be addressed by empirical studies is whether hand preference is a downstream manifesta-tion of the development of hemispheric differences in sensory processing and cognition, or whether it is instrumental in the development of functional differences between the hemispheres. Comparison is made to paw preference and associated behaviour in non-primate species.