Conceptual and lexical hierarchies in young children

Linguistic form and conceptual level both play a role in the structure of adult lexical hierarchies. The present studies examined how these factors might affect acquisition. In their linguistic form, labels can be single nouns (e.g., oak) or compound nouns (e.g., oak-tree). In conceptual level, categories can be structured at the basic (e.g., tree), superordinate (e.g., plant), or subordinate (e.g., oak) levels. Both of these factors were varied in two experiments, in which 133 children, aged 2;11 to 5;11, were taught novel lexical hierarchies. As predicted, compound nouns were easier to learn than single nouns, especially at the subordinate level. Age of child and category level influenced the kinds of errors children made. The most common error was to treat hierarchically related words as labeling mutually exclusive subsets (analogous to oak and e/m, for example), so that terms from different levels contrasted at the same level. Both factors--linguistic form and conceptual level--influence d learning of new lexical hierarchies.