LAUSR

Abstract Achievement goals have been a key issue in research on motivation over the last three decades. However, few longitudinal studies have been conducted on sex differences in the development of achievement goals in middle school. The aim of this study is to provide information on this issue. Therefore, we assessed the mastery, performance-approach, and performance-avoidance goals in 6853 students who completed questionnaires in Grades 5, 7, and 9. The achievement goal construct remained stable over time and across sex. Latent growth curve analyses indicated that all achievement goals declined throughout middle school and latent difference score models illustrated that the greatest decline occurred between Grades 5 and 7. While girls reported higher levels of mastery goals throughout middle school, there was a stronger decline of performance goals in boys during this period. Our findings underline the importance of exploring the development of achievement goals in greater depth.