Relationship Between Count/Mass Nouns and Shape/Material Biases in Novel Word Learning Tasks

Children use biases to learn novel words and extend these words to novel objects without having to give consideration to every possible meaning of the new word. Using Novel Noun Generalization Tasks, researchers have found that children 2-years-old tend to extend names for solid objects to other objects that are the same shape, which is called the shape bias (Landau, Smith, \u26 Jones, 1988; Soja, Carey, \u26 Spelke, 1991; Imai \u26 Gentner, 1997). Children 2½-yearsold also extend names for non-solid substances to things that have the same material, which is called the material bias (Dickinson, 1988; Soja 1992; Imai \u26 Gentner, 1997; Landau, Smith, \u26 Jones, 1992; Diesndruck \u26 Bloom, 2003). In early vocabulary, count nouns tend to refer to solid objects and mass nouns tend to refer to non-solid substances (Samuelson \u26 Smith, 1999). This study tests whether a child’s knowledge of count and mass nouns at age 24 months influences their performance on two NNGTs, one using solid objects and one using non-solid substances. Our results found that total number of nouns (count, mass, and ambiguous) in a child’s vocabulary does influence whether they exhibit the shape or material biases for either solid objects or non-solid substances. 24-month-olds with a larger noun vocabulary tend to extend the names of both solid objects and non-solid substances to shape, and 24-month-olds with a smaller noun vocabulary tend to extend the names of both solid objects and non-solid substances to material. We also found that both a larger number of count nouns and pro-shape bias words (nouns that describe categories of objects that are solid and match in shape) is negatively correlated with whether children pick material matches for solid objects. Thus, the more count nouns and pro-shape bias words a child has, the less likely they are to choose material matches for solid objects. These results show that attending to shape, not material, can create a larger vocabulary in 24-month-olds