Perception of contradictory speech by normal and disturbed children at various age levels.

Recordings were made of female teachers reciting congruent and contradictory messages. In the congruent condition, the verbal and tonal elements of the communication were consistent. With the contradictory speech, however, the tone of voice was incongruent with the words spoken. All the congruent and contradictory vocal expressions were arranged in random order on a single tape and played to "normal" and "disturbed" boys of different ages (i.e., grade levels 2, 4, and 6). Significant effects were found for type of speech and age: Subjects reacted more negatively to contradictory than to congruent speech, and younger children responded more negatively to contradiction than did older ones. As well, contradictory speech seemed to have more of an impact on the disturbed boys— they reacted significantly more negatively to contradictory messages than the normal youngsters.