Tested whether 7-month-olds' means-end behaviors were genuine or the repetition of trained behaviors under conditions of greater arousal. Found that infants' learned button-pushing to light a set of distant lights differed from button-pushing to retrieve toys. Infants demonstrated means-end skills with behaviors that they had not been trained to…

Tested 4-month-olds' memory for surface feature and location information following brief occlusions. Found that when target objects were images of female faces or monochromatic asterisks, infants increased looking times following changes in identity or color but not changes in location or combinations of feature and location. When objects were…

Two studies examined whether object names and functions act as cues to categories for infants. Findings indicated that both 14- and 18-month-olds were more likely to select the category match after being shown a novel category exemplar with its function than when given no additional cues. Only at 18 months did naming the objects enhance…

This study examined whether 9.5-month-olds could use featural information to individuate objects. Results suggest that infants categorize events involving opaque and transparent occluders as the same kind of situation and that infants are more likely to give evidence of individuation when they need to reason about one kind of event than when they…

Four experiments examined 8-month-olds' ability to reason about collections of objects. Findings suggested that infants' expectations about object behavior do not automatically apply to any and all portions of matter within the visual field. The behavior of an entity and infants' prior experience played roles in determining whether infants will…

Five experiments demonstrated that 6.5-month-olds perseverated in a violation-of-expectation task to examine reasoning about width information in containment events. After watching a familiarization event in which a ball was lowered into a wide container, infants failed to detect the violation when the same ball was lowered into a container half…

Examined the nature of numerical knowledge in 5-month-olds to inform the debate whether numerical abilities result from capacities dedicated to numerical cognition or to more general perceptual capacities. Found that 5-month-olds could determine the number of collective entities, moving groups of items, when non-numerical perceptual factors such…

Examined three possible explanations for findings that infants detect textural discrepancies based on individual features more readily than on feature conjunctions. Found that none of the proposed factors could explain 5.5-month-olds' superior processing of featural over conjunction-based textural discrepancies. Findings suggest that in infancy,…

Four experiments examined very young infants' expectations about containment events. Found that 2- to 3.5-month-olds recognized that objects could be lowered inside a container with an open but not a closed top. Three-and-a-half-month-olds realized that objects could not pass through the container's back wall and should have moved with it to a new…

Examined whether 6-month-olds expect people to behave differently toward persons and inanimate objects. Found that infants habituated to an actor talking to something hidden behind an occluder looked longer at an object, whereas infants habituated to an actor reaching and swiping looked longer at a person. No difference in looking at stimuli was…

Two experiments examined whether associating an imitation task with an operant task affected 6-month-olds' memory for either task. Results indicated that infants successfully imitated a puppet's action for up to 2 weeks only if the associated operant task (pressing a lever to activate a miniature train) was retrieved first. Follow-up study…

Four studies examined whether 16-month-olds' responses to true/false utterances interacted with their knowledge of human agents. Findings suggested that infants are developing a critical conception of human speakers as truthful communicators and that infants understand that human speakers may provide uniquely useful information when a word fails…

Examined infants' ability to retrieve an object from atop a slightly larger object. Found that even 5-month-olds could retrieve objects close in size and fully contiguous with their bases when demands on reaching skill were reduced. Proposed that when they fail this task, it is because they lack the skill to reach the top object without…

Three longitudinal studies examined means-ends behavior of 6- to 8-month olds. Found that intentional means-end behavior increased between 6 and 7 months, with 7-month olds' performance influenced by the presence of a toy on the cloth. Performance was the same when cloth was attached to or separate from the toy. By 8 months, infants adjusted…

Two studies examined whether infants' category discrimination in an object-examination task was based solely on an ad hoc analysis of perceptual similarities among the experimental stimuli. Findings indicated that 10- to 11-month- olds' responses varied systematically only with the presence of a category change, but not with the degree of…