In recent years, discussion of the limitations of the standard cross-lagged panel model (CLPM) has increased, and the random intercept cross-lagged panel model (RI-CLPM) has been proposed as an improved approach to modeling. By now, there are some first applications of the model to investigate reciprocal relations in self-concept development. However, a methodological-substantive integration of the model in the context of the three major comparison processes in self-concept development is still missing, and it has not been used to evaluate dimensional and temporal comparison effects. We provide such an integration in self-concept theory and applied the RI-CLPM to investigate social, dimensional, and temporal comparison effects simultaneously. Investigating a sample of 701 German students from the middle of Grade 9 to the middle of Grade 10, we confirmed previous results by finding trait-like stability in science, technology, engineering, and mathematics (STEM) self-concept as well as in STEM and language achievement. We also found evidence for all three comparison effects, but evidence for dimensional comparison effects was only found at the between-person level of the RI-CLPM.
Public Significance StatementThis study explains why a recent and still rarely applied modeling method has many advantages to investigate the three major processes of academic self-concept development: comparisons with others, internal comparisons between different subjects, and comparisons with the past. Applying the method confirmed the relevance of these processes and highlighted the importance of appropriately modeling the relatively high stability of self-concepts to obtain accurate results and, consequently, to improve intervention design.