This thesis investigates academic self-concept, defined as students’ perceptions of their academic ability. Academic self-concept is an important construct in educational psychology, both as an outcome of students’ academic experiences and as a predictor of later educational and life outcomes. Although previous research has shown that academic self-concept is related to achievement, motivation, educational choices, and attainment, questions remain regarding how it is formed, how it develops during adolescence, and how it is associated with outcomes beyond the educational system.