Previous research suggests that model competence does not emerge until relatively late in infancy (20-26 months). Development was systematically analyzed within 3 key areas--count noun learning, dual representation, and categorization--hypothesized to support the emergence of model competence in the second year. In an object-handling preferential…

Three experiments explored effects of stimulus and task factors on tendency to categorize according to taxonomic relations when those relations conflict with appearances. When provided with information that constrained categorization, preschoolers and adults reliably based their decisions on taxonomic relations between physically dissimilar items.…

Three experiments using the familiarization-novelty preference procedure confirmed the hypothesis that three-month-old infants could form categorical representations of spatial relations above and below. The infants, after being shown a familiarization diagram with a dot appearing in multiple locations below a line, showed a preference for a novel…

Confirms that infants, like older children, are capable of responding categorically to stimuli of different shapes if these are similar in hue. (PCB)

Three experiments examined how flexibly two- to four-year-old children use the words "big" and "little" in normative, perceptual, and functional contexts. Results showed that children switched easily from a normative context but made errors when asked to switch to a normative context. (MDM)

Children often perseverate, repeating prior behaviors when inappropriate. This work tested the roles of verbal labels and stimulus novelty in such perseveration. Three-year-old children sorted cards by one rule and were then instructed to switch to a second rule. In a basic condition, cards had familiar shapes and colors and both rules were stated…