Five experiments used a categorization habituation-of-looking paradigm to investigate infants' categorization of animals and vehicles based on static versus dynamic attributes of stimuli (color images versus dynamic point-light displays). Findings showed that 6-month-olds categorize animals and vehicles based on static and dynamic information, and 9-month-olds, but not 6-month-olds, can transfer dynamic category information to static images. (Author/KB)