The role of imitation in the stabilization of handedness during infancy.

Only about 50% of infants appear to be right-handed in their first year, yet only 10-12% ultimately become left-handed. Several parameters may control early changes in handedness, and we investigated the role of imitation. We wanted to see if infants, when choosing the hand to manipulate an object, were influenced by the hand used by the experimenter when demonstrating the target action. We observed infants, seated either opposite or on the lap of the experimenter who used either left or right hand. The results show that when a left-handed experimenter demonstrated the action, none of the infants consistently used a right-handed strategy to manipulate the objects, regardless of the position (lap vs. opposite), and even though most infants had shown right-handedness when first grasping the objects. Imitation may thus be part of the parameters that stabilize infant right-handedness, or, on the contrary, that drive infants towards left-handedness.