On intersubjective engagement in autism: a controlled study of nonverbal aspects of conversation.

Does autism involve a deficit in intersubjective engagement with other persons? We studied nonverbal communication in children and adolescents with and without autism (n = 12 per group), group-matched for chronological age and verbal mental age, during 3 min of a videotaped interview. In keeping with previous studies, there were only subtle but potentially revealing group differences on behavioral ratings. Participants with autism made fewer head-shakes/nods (but not smiles) when the interviewer was talking, and the interviewer made fewer head-shakes/nods when participants were talking. Yet there were marked group differences on reliable 'subjective' ratings of (a) affective engagement and (b) the smoothness of reciprocal interaction. We interpret the findings in terms of a group difference in identification between conversational partners.