A little goes a long way: evidence for a perceptual basis of learning for the noun categories count and mass

Various theories of learning for the categories count noun and mass noun are compared. It is argued that children assign words to these categories on the basis of intuitions arising from perception that are relevant to Macnamara's (1986) semantic definitions of the categories. These definitions rest on the centrality of identity in the meaning of nouns and the centrality of individuation in the meaning of count nouns but not mass nouns. Empirical evidence is presented that supports the hypothesis that young children classify words as count nouns or mass nouns on the basis of perceptual information about the extension of the words, that is, whether or not the extension consists exclusively of enduring individuals whose discreteness from one another is perceptually salient (count nouns) or not (mass nouns). In an experiment, 48 children with a mean age of 2;10 (S.D. = 0;5) were taught a word for a kind of object (i.e. a perceptually distinct individual) or for a kind of substance (i.e. a collection of small granules). For some children the word was syntactically count and for others it was syntactically mass. Half of the children received incongruous perceptual and syntactic cues. For most of these children, classification of the word was guided by the object- or substance-like appearance of the stimulus despite the presence of incongruent syntactic cues. Syntactic cues influenced classification of the word for a minority of subjects, most of whom were among the oldest in the sample. It is concluded that perceptual information is critical in early decisions about membership in the categories count noun and mass noun.