Naming and categorization in young children: II. Listener behavior training.

Following pretraining with everyday objects, 1- to 4-year-old children received listener training with three pairs of arbitrary stimuli of differing shapes. For each pair, 9 children were trained to select one stimulus in response to the spoken word /zog/ and the other to the spoken word /vek/. Next, in the look-at-sample category match-to-sample test, none categorized the six stimuli correctly when asked to look at the sample before selecting from five comparisons. Seven of these children failed a subsequent test of corresponding speaker behavior (tact test); following tact training, 5 of them passed either a repeat of the look-at-sample category test (2 subjects) or an alternative category test (3 subjects) in which they were required to tact the sample before selecting comparisons. The remaining 2 failed both category tests. Of the 2 who passed the tact test, 1 passed the tact-sample category test; the other failed to complete category testing. Two children were next given a second stimulus set. One passed the look-at-sample category test and the tact test; the other failed both tests but passed the tact-sample category test after tact training. The results show that 1- to 4-year-old children may learn listener behavior without corresponding speaker behavior. The results also show that common listener behavior is not sufficient to establish arbitrary stimulus classes, and they are consistent with the proposition that naming may be necessary for categorization of such stimuli.