Children's Ability to Detect Semantic Contradictions

Numerous studies of semantic memory have explored the processes by which adults use information about word meanings to evaluate the veracity of simple sentences such as "A rose is a flower" (Collins & Quillian 1969; Glass, Holyoak, & O'Dell 1974; Loftus 1973; Rips, Shoben, & Smith 1973; Wilkins 1971). In these studies, the subject's latency to indicate whether a sentence is true or false has typically been the main dependent measure, since accuracy is generally very high. An important developmental question is how the semantic organization of the adult develops in the child. Is semantic information acquired by a cumulative process, or is it substantially reorganized at various stages of development? Do children and adults show a similar pattern of difficulty for different types of sentences? To show a link between child and adult performance in sentence-verification tasks, one could provide evidence that differences in adult latencies to verify sentences are paralleled by the order in which children learn to assess correctly the validity of the sentences. Rosch (1973) has provided such evidence for one class of true sentences. She presented both adults and children (9-11-year-old boys) with true and false sentences asserting that an instance was a member of a category (e.g., "A ball is a toy"). She found that for both age groups those true sentences containing frequently produced instances of the predicate category (from the norms of Battig & Montague [1969]) were verified more quickly than sentences containing less frequent instances (e.g., "A ball is a toy" vs. "A swing is a toy"). The children also had a much lower error rate with the frequent than with the less frequent items. Since these errors were made under time pressure, this result does not necessarily mean that the children sometimes did not know that the less frequent instances were members of the predicate category. Nevertheless, Rosch's data are consistent with the hypothesis that those true sentences that adults are quickest to verify are assessed correctly by children at the earliest age.