Infants can rapidly form new categorical representations.

Young infants learn common categorical distinctions, such as animals versus vehicles. But can they, like adults, rapidly form new categories, such as black-and-white animals? To answer this question, 6-, 10-, and 13-month-old infants were familiarized with four land animals that were black and white in coloring (e.g., a zebra and a black-and-white tiger) and then were tested with novel animals and a truck. The infants responded to an exclusive category that apparently included only black-and-white animals, suggesting that they formed a new categorical representation during familiarization. A comparison group of infants familiarized with a set of land animals that were more variable in coloring (e.g., a pale yellow horse and a yellow-and-brown tiger) formed a very general categorical representation that included many different kinds of animals, regardless of coloring. Therefore, like adults, infants rapidly form new categorical representations in response to the context.