Children's beliefs about why affective expressive behavior should be dissociated from internal state were elicited via a structured interview and investigated in conjunction with their parents' (1) attitudes toward children's expressive behavior, (2) perceptions of their own self-monitoring, and (3) perceptions of their families'"social climate." Participating were 32 children in the second, fifth, and eighth grades of an urban west coast parochial school. Children, distributed approximately equally by age and sex, responded to four photographed scenarios of conflicts in which a depicted child could respond with a facial expression that was discrepant from internal affect. This procedure previously had yielded significant age differences in reasoning about the dissociation of affect and expressive behavior. In addition, children were asked about the justification for regulating expressive behavior, the interpersonal consequences of regulation, and the ways they balanced showing or not showing real feeling. The children's parents responded to the Parent Attitude toward Child Expressiveness Scale, to Snyder's Self-Monitoring Scale, and to Moos' Family Environment Scale. Data were analyzed by means of stepwise regression analyses for each of the three child variables. As expected, age was found to be signifiantly related to all of the three variables. Additional results indicated the effect of maternal and paternal attitudes on children's beliefs. (RH)