A new structural equation modeling approach to questions of the direction of causal flow between global and specific multidimensional measures of self-concept (SC) in two 2-wave, longitudinal studies demonstrated that (a) higher order factors were unable to explain relations among first-order factors at Time 1 (T1), at Time 2 (T2), or between T1 and T2; (b) T1 global SC had little effect on specific SC factors at T2 (a top-down model), but specific factors at T1 had even less effect on T2 global SC (a bottom-up model); and (c) many specific factors were more stable than global factors, but higher order factors were most stable. Results provide little support for top-down, bottom-up, or reciprocal models, instead arguing for a horizontal model in which each T2 SC factor is primarily a function of the matching T1 SC. This casts further doubt on the usefulness of hierarchical representations of SC.