This paper presents results from a study of the effects on student development of open and traditional family and school environments. The theory is entertained that a match (or congruence) of family and school styles improves some student outcomes, while a mismatch (or incongruence) of environments results in improvement of different student outcomes. Using survey data from 4,079 white students in grades 6, 7, 9 and 12 in 16 secondary schools in Maryland, tests for interaction effects fail to reach accepted levels of significance consistently across grades for any outcome or within grades for multiple outcomes by any family environmental dimension. Instead of interpretable family-school interactions, there are important main effects. Particular family and school conditions have consistently significant, positive consequences throughout adolescence for the seven student outcomes. At all grade levels greater participation in family decisions is associated with more positive personality development and school coping skills; greater participation in classroom decisions are related to more positive school coping skills; and higher family socio-economic status is important for higher aspirations. The study demonstrates the benefits of using specific family and school environmental measures to supplement standard social class variables for better understanding of educational processes. (Author)