How do self-concept differentiation and self-concept clarity interrelate in predicting sense of personal identity?

•Two alternative models linking self-concept differentiation and self-concept clarity with sense of identity were tested.•Self-concept clarity fully mediated (but not moderated) the self-concept differentiation's effect on sense of identity.•Self-concept differentiation had no direct effect on sense of identity.

Research has established that there are individual differences in the self-structure, and that they are relevant for an individual's psychological and social functioning. However, little is known about how they interrelate to predict certain outcomes. The present study focused on two such individual differences – self-concept differentiation and self-concept clarity – and examined the influence of self-concept clarity on the relationship between self-concept differentiation and sense of identity, first as a mediator, and secondly as a moderator. Self-concept clarity was found to mediate this relationship, with no direct effect of self-concept differentiation on sense of identity. No support was found for the moderating effect of self-concept clarity. Results are interpreted as extending previously reported data regarding the relative independence and significance of the two constructs.