Self-Complexity and Self-Concept Differentiation – What Have We Been Measuring for the Past 30 Years?

Research on the relation between the structure of the self-concept and psychological well-being has yielded seemingly inconsistent and even conflicting results. This article presents studies that examined the validity of often-used measures of self-complexity and self-concept differentiation and tested their ability to predict personal identity and active cognitive processing. The findings revealed several conceptual and methodological problems that continue to plague self-structure research, including the conflating of self-concept content and self-concept structure. In short, our data indicated that the commonly used indices of self-complexity and self-concept differentiation cannot be considered pure measures of the underlying dimensions of self-structure. In addition, only weak correlations of the self-structure variables with measures of personal identity and thinking dispositions have been found. Moreover, once the theoretically irrelevant sources of variance were controlled, the effects of the included structural features of the self-concept on the outcomes of interest either did not occur or were less pronounced. Given the above, it seems reasonable to suggest that at least some of the conclusions regarding the adaptive value of self-structural variables drawn from previous research in this field need revision.