Examined are the relationships of student responsibility and parent-adolescent relations to the school performance of middle-school-age youth. A total of 120 families with a first-born child between 11 and 16 years of age participated in the study. Assessment of adolescent responsibility included measures of self-reliance, work orientation, resistance to peer pressure, and involvement in household responsibilities. Assessment of the parent-child relationship included measures of decision-making, parental acceptance, and parental control. Measures of school performance were students' English and mathematics grades, attendance records, and standardized achievement test scores. In general, cross-sectional analyses indicated that adolescent responsibility and a constellation of parenting practices described as "authoritative" are associated with school success. However, longitudinal analyses indicated that responsibility is a correlate, rather than an antecedent, of school success, whereas authoritative parenting actually enhances school performance. For reasons not yet fully understood, youngsters whose parents are relatively less permissive, more accepting, and less psychologically controlling do better in school than do their peers. (RH)