Children's use of lexical flexibility to structure new noun categories

Because most common words have multiple meanings, children are often learning new senses of existing words, rather than entirely new words. Here, we explore whether children can use their knowledge of an existing word sense to constrain their interpretation of a new word meaning. Across two studies, we teach 3and 4-year-olds and adults novel words for materials, and manipulate whether those words are also used flexibly, to label objects made from those materials. We find that participants of all ages assign markedly different interpretations to the object labels when they have a prior, material meaning: Rather than extending them to other objects of similar shapes, they extend them on the basis of shared material, thus overriding the well-documented shape bias. These findings suggest that language learners can use a word’s prior meaning to learn about the structure of its new meaning.