Abstract
Stacking is a hallmark of fine motor skill development and requires skilled hand use. One mechanism for children to gain manual proficiency involves establishing a hand preference that creates practice differences between the hands as the preferred hand is used more often and in different ways than the other. Prior work found that stacking skill emerged earlier for infants with an identifiable hand preference. However, it is not known how hand preference relates to later toddler stacking performance. This study examined the effects of early hand preference (infant pattern), concurrent hand preference (toddler pattern), and consistent hand preference (infant to toddler pattern) on toddler stacking skills. Sixty-one toddlers, whose hand preferences as infants were known, were assessed for their toddler hand preference and their stacking skill across 7 monthly visits from 18 to 24 months of age. Using multilevel Poisson longitudinal analysis, children with hand preferences that were consistent across both infancy and toddlerhood were more successful at stacking, compared to those with inconsistent preferences across the infant and toddler periods. Thus, consistency of hand preferences during the first 2 years likely contributes toward individual differences in the development of fine motor skills.