Preschoolers' selective learning is guided by the principle of relevance.

We investigate whether preschoolers' word learning is selectively attuned to learning word-referent links that they expect will be relevant to their everyday communicative contexts. In two studies, 4-year-olds were taught the name of an unfamiliar toy that they were told was purchased either nearby or faraway. Children's memory for the link was assessed either by a speaker who was not present when it was taught or by the same speaker who taught it to them. Children who were told that the toys were from nearby learned the word-referent link, whereas children who were told the toys were from faraway did not. Our findings suggest that 4-year-olds' word learning is "attuned to relevance" - they selectively acquire new word meanings that will have communicative utility in their linguistic community. These findings provide the first evidence that children's selective word learning is driven by an overarching principle of prospective relevance.