Out of the Mouths of Babes: The effect of source on 20-month-olds ’ Use of Mutual Exclusivity

One account of word learning suggests that children learn that words are unique as labels among perceptual signals because of the way they tend to systematically co-occur with catego-ries of objects. Twenty-month-old’s use of mutual exclusivity with different types of labels emanating from different sources was investigated in order to evaluate this account. Specifically, words and animal sounds were investigated. Re-sults showed that children applied mutual exclusivity to both words and animal sounds produced by mouths, but not to words or animal sounds produced by noisemakers. This sug-gests the importance of including the regularities of social context and pragmatics to the associationist account of word learning