Infant manual exploration of objects, surfaces, and their interrelations

Although a considerable amount is known about the development of object manipulation during the 1st year, less is known about how infants manually explore surfaces and relate objects to surfaces. To address these issues, 60 infants (20 each at 6, 8, and 10 months of age) were presented hard and soft objects on tabletop surfaces, which varied in terms of their material properties. Tabletop surfaces were either liquid, discontinuous, flexible, or rigid. Results indicated that infants explored the objects, surfaces, and their interactions selectively, tailoring their manual actions to the material properties of the objects or surfaces. In some instances, selectivity increased with age. The implications of these findings for understanding the origins of problem solving and tool use are considered.