This paper examines stability and change during the elementary-to-middle school transition, focusing on adolescents' experiences of home--school dissonance because of real or perceived differences between home/self and values within the school context. Relationships were hypothesized between exacerbation and amelioration of dissonance, middle school mastery and performance goal practices, and students' perceptions thereof. The sample consisted of 274 African-American and 284 European-American (49% female) students. Middle school teachers ("N" = 236) provided data on school academic practices. Multilevel growth curve analysis indicated significant variance among the 10 middle schools regarding change in dissonance. Both mastery-focused middle school practices and students' perception of middle school classrooms as more performance and less mastery focused than elementary classrooms were significant predictors of change in dissonance. Path-analyses evidence pointed to the mediational role of school belonging on the relationship between perception of classroom mastery goals and dissonance. Path analyses revealed direct and indirect effects of perception of classroom performance goals on dissonance and school belonging. This paper highlights the importance of creating inclusive learning environments that minimize social comparison saliency and validate students for who they are.