We (Marsh & Craven, 1997) have claimed that academic self-concept and achievement are mutually reinforcing, each leading to gains in the other. Baumeister, Campbell, Krueger, and Vohs (2003) have claimed that self-esteem has no benefits beyond seductive pleasure and may even be detrimental to subsequent performance. Integrating these seemingly contradictory conclusions, we distinguish between (a) older, unidimensional perspectives that focus on global self-esteem and underpin the Baumeister et al. review and (b) more recent, multidimensional perspectives that focus on specific components of self-concept and are the basis of our claim. Supporting the construct validity of a multidimensional perspective, studies show that academic achievement is substantially related to academic self-concept, but nearly unrelated to self-esteem. Consistent with this distinction, research based on our reciprocal-effects model (REM) and a recent meta-analysis show that prior academic self-concept (as opposed to self-esteem) and achievement both have positive effects on subsequent self-concept and achievement. We provide an overview of new support for the generality of the REM for young children, cross-cultural research in non-Western countries, health (physical activity), and nonelite (gymnastics) and elite (international swimming championships) sport. We conclude that future reviews elucidating the significant implications of self-concept for theory, policy, and practice need to account for current research supporting the REM and a multidimensional perspective of self-concept.