Two studies exploited a new manual search methodology to assess the bases on which 10- to 12-month-olds individuate objects. Infants saw 1 or 2 objects placed inside an opaque box, into which they could reach. Across conditions, the information specifying 2 objects differed. The dependent measures reflected persistence of reaching into a box that was empty regardless of whether an object should have remained. Success consists of little reaching after all objects are removed and persistent reaching for an object not yet retrieved. Given spatiotemporal information for 2 objects, both age groups succeeded. Given only property or kind information, only 12-month-olds succeeded. Despite disparate information-processing demands, this pattern converges with looking time data (Xu & Carey, 1996; Xu, Carey, & Welch, 1999), suggesting a developmental change orthogonal to that of executive function. This change may reflect the emergence of kind representations.
ASJC Scopus subject areas
- Experimental and Cognitive Psychology
- Developmental and Educational Psychology
- Psychiatry and Mental health