Categorization in infancy.

Human infants display complex categoriztion abilities. Results from studies of visual preference, object examination, conditioned leg-kicking, sequential touching, and generalized imitation reveal different patterns of category formation, with different levels of exclusivity in the category representations formed by infants at different ages. We suggest that differences in levels of exclusivity reflect the degree to which the various tasks specify the relevant category distinction to be drawn by the infant. Performance in any given task might reflect prior learning or within-task learning, or both. The extent to which either form of learning is deployed could be determined by task context.