Hand Movements in Communicative and Noncommunicative Situations in Very Young Infants: A Preliminary Study

As a step toward understanding the developmental relationship between handedness and language lateralization, this longitudinal study investigated how infants (N = 21) move their hands in noncommunicative and communicative situations at 2 weeks and at 3 months of age. The authors looked at whether left-right asymmetry in hand movements and in duration of self-touch appeared across conditions and whether the direction of asymmetry depended on the communicative nature of the situation. The authors found that asymmetries appeared less consistently than suggested in literature and did not only depend on the communicative nature of the situation. Instead, hand activity and self-touch patterns depended on age, the presence of the mother, the degree of novelty of the situation, and the presence of an object. The results partly support previous studies that pointed out an early differentiation of communicative hand movements versus noncommunicative ones in infants. It is in terms of the amount of global hand activity, rather than in those of the laterality of hand movements that this differentiation emerged in this study. At 3 months, infants moved their hands more in the communicative conditions than in the noncommunicative conditions and this difference appeared as a tendency already at 2 weeks of age.