Abstract
In two experiments with 36 human infants, we asked whether 3β and 6βmonthβolds could use correlations between attributes of individual objects to categorize. Infants learned to kick to move block mobiles that simultaneously displayed two categories defined by the figures displayed on them: the colors of the figures and the colors of the blocks. Two features were correlated, and the third varied across categories. Only 6βmonthβolds categorized novel category exemplars that preserved the original feature correlations (Experiment 1A), but both 3β and 6βmonthβolds discriminated feature recombinations that broke the original correlations (Experiment 1B). When category exemplars were presented successively, 6βmonthβolds also learned the feature correlations and used them to categorize (Experiment 2), but their performance was less robust. Infants' superior learning when stimuli were presented simultaneously may reflect βunitization,β a learning disposition unique to immature infants. These experiments reveal that infants' ability to use correlated attributes to categorize emerges months earlier than previously thought. Β© 2004 Wiley Periodicals, Inc. Dev Psychobiol 44: 103β115, 2004.