This study examined the stability of self-monitoring in children and the relationship between self-monitoring and personality and family variables. Participants were 93 1st-, 3rd-, and 5th-grade children and their parents. Children completed the Junior Self-Monitoring Scale, Eysenck Personality Questionnaire, Pictorial Scale of Perceived Competence and Social Acceptance for Young Children (1st graders) or the Self-Perception Profile for Children (3rd and 5th graders), and a sociometric scale. Self-monitoring was stable for all children across a 15-month interval. As expected, self-monitoring was moderately related to extraversion, and for boys, higher self-monitoring scores were related to peer popularity and self-esteem. Children's self-monitoring was not related to their parents' self-monitoring, but was related to their ordinal position in the family and the number of children in the family.Individual differences in the construct of social self-monitoring have been extensively examined among adults, primarily using Snyder's (1974Snyder's ( , 1979 Self-Monitoring Scale (SMS). According to Snyder's conceptualization, high self-monitoring adults (HSMs) prototypically adopt an interpersonal orientation and intentionally use the behaviors of others as guidelines for their own appropriate verbal and nonverbal self-presentation. In contrast, low self-monitoring adults (LSMs) are less motivated to monitor the social environ ment and are more concerned with their own personal dispositions, affective states, and attitudes.The range of conceptually relevant adult social behaviors associated with self-monitoring is wide and cannot be completely summarized here (for a review, see Snyder, 1987). However, research indicates that HSMs are better than LSMs at describing the behaviors that would produce a desired impression in a social situation (Snyder & Cantor, 1980). High self-monitors also engage in more reciprocal self-disclosure (Shaffer, Smith, & Tomarelli, 1982), use social comparison information more frequently and for longer durations (Elliott, 1979), and are more likely to behave in ways that are inconsistent with their verbally expressed attitudes (Paulhus, 1982) than are LSMs. Self-monitoring is moderately related to extraversion and exhibitionism (Lippa, 1976; Snyder, 1987) but unrelated to Machiavellianism, repression-sensitization, and public or private self-consciousness (Snyder, 1987).