Self-concept of ability refers to the perception of one’s capability to successfully perform on academic tasks. This may explain academic achievement. It is possible that young children successfully perform various academic skills which develops a positive view on those skills, making it more likely that they engage with these skills and become proficient in them. A positive perception of skill could be increased by peer comparison and positive feedback.When a student feels competent, this sense of ability may enhance one’s self-concept, allowing the student to persist at and seek out activities that further influence academic achievement. This means that a positive self-perception of abilities may promote academic achievement. Early math achievement predicts later math achievement even when controlling or child characteristics, background and demographic variables and early reading achievement also predicts later math achievement. Self-concept of ability in math between the ages 9 and 14 is related to later math achievement even when taking into account earlier math and reading achievement and other variables (e.g. demographics). Self-concept of ability in reading in middle childhood is not related to later math achievement. This association holds across the achievement spectrum (i.e. high- and low achievers). Self-concept of ability in reading in middle school predicts later reading achievement even when taking into account earlier achievement and other variables. Self-concept of math does not predict reading achievement. This relationship holds across he achievement spectrum but there is a smaller association between reading self-concept and reading achievement when achievement is high compared to when achievement is lower.Self-concept of ability plays an important role in motivating achievement over time and across achievement levels. It is possible that these beliefs playa stronger role for students not achieving at higher levels...