Categorization of geometric figures composed of three or four elements by 3-month-old infants

The capacity of infants to perceptually categorize multidimensional geometr ic figures has been demonstrated in 5.5-month-old infants using an infant-c ontrol procedure. The present study investigated this capacity at the age o f 3 months. Six experiments were conducted using the visual habituation par adigm. Habituation stimuli were presented. Each stimulus was composed of th e same number of elements that always differed in arrangement and sometimes differed in shape. Novel test figures which either belonged or did not bel ong to the same category were then presented. The results showed that the t est stimuli were always processed differently, regardless of the number of elements in the habituation phase (4 or 3) or on the test (3 or 4). Three o f the control experiments demonstrated (a) the ability of 3-month-olds to d iscriminate stimuli from the most similar categories, (b) no stimulus area effect, and (c) no preference for a figure composed of three versus four el ements. Three-month-old infants can evidently learn categories in the conte xt of multidimensional figures. Young infants' categories, like those of ol der infants, appear to be based on element quantity and/or configuration.