Rated videotaped verbal and nonverbal (smiling) behavior of parents in interaction with their children. The socioeconomically matched sample included 20 families containing a disturbed child and 20 normal control families. An interaction was predicted and confirmed (p = .05) between parent sex and facial expression; i.e., when a father smiled, he was making a friendlier or more approving statement than when he was not smiling; for mothers, there was no difference in the evaluative content of verbal messages when she was smiling vs. when she was not smiling. This pattern was found to be unrelated to child disturbance. Findings were, however, limited to middle-class families because the majority of lower-class mothers in this sample did not smile at all. (16 ref.) (PsycINFO Database Record (c) 2016 APA, all rights reserved)