Relation of stable hand-use preferences to the development of skill for managing multiple objects from 7 to 13 months of age.

Expression of multiple object management skills (manual acquisition and storage of objects) was examined longitudinally at 7, 9, 11, and 13 months for 38 infants (19 females) whose hand use preference was either stable (consistently right or left across the ages) or nonstable (either no hand-use preference exhibited or inconsistent preference across the ages). Four separate sets of four distinctive objects each were presented singly to the infant's right and left side, with the presentation of each subsequent object contingent on the infant manipulating the previous object. Expression of multiple object management skills significantly increased with age. Infants with stable hand-use preferences produced more object acquisition and storage acts than those without a stable hand-use preference. Older infants with stable hand-use preferences exhibited more "sophisticated" sequences of multiple object management acts than those without. The role of stable hand-use preference in the development of manual skill and cognition is discussed. (c) 2008 Wiley Periodicals, Inc.