Studied 16 six-month-old infants to determine whether they organized speech categories around prototypes. Infants correctly sorted novel stimuli over 90 percent of the time. Generalization to novel members of the category was significantly greater after exposure to the prototypical exemplar. (RJC)

Twelve two year olds were taught novel count nouns for related but unfamiliar objects. Children's interpretation of the relations between the nouns was mediated by the similarity of the objects, a result that suggests that, by age two, children have the conceptual and lexical abilities necessary for establishing hierarchical relations. (LB)