Incorporating new words into the lexicon: preliminary evidence for language hierarchies in two-year-old children.

In 4 experiments, we examined how young children incorporate new word meanings into their lexicons. 2-year-olds were each taught a new noun for an object that already had a known label (e.g., a "fep" for a dog). Children's interpretations of the new nouns were assessed by asking subjects to select the named toy from an array of 4 toys (e.g., "Point to a fep"). The experiments were designed to determine which of several possible semantic relations between novel and familiar words was most consistent with children's performance. It was found that children often seemed to interpret the new word as referring to a subordinate of the known category. This tendency was reduced when the named object could sensibly receive a proper name (e.g., when the named object was a stuffed animal), particularly when children had to consider both the familiar and the novel label for the object in the same session. Although not all alternative explanations have been ruled out, these results suggest that, from a very young age, children may spontaneously form language hierarchies when they hear a novel work for an object that already has a familiar name.