Longitudinal self-concept development in adolescence.

This longitudinal behavioral neuroimaging study tested two hypotheses concerning self-concept development in adolescence: domain-specific self-concept and similarity between own (direct) and perceived peers' (reflected) opinions of the self. Participants (N=189; 10-24 years) evaluated their traits in academic, physical appearance, and prosocial domains from direct and reflected perspectives in an fMRI session across three timepoints (TP1: N=160; TP2: N=151; TP3: N=144). Behaviorally, we observed a mid-adolescent dip in self-concept positivity, which was strongest for the academic domain, showing domain-differentiation in mid-adolescence. Self-evaluations were associated with activity in e.g. medial Prefrontal Cortex (mPFC) and Temporal Parietal Junction (TPJ). mPFC showed an adolescent-emerging peak in activation, pronounced more for direct than reflected self-evaluations. TPJ activation was generally stronger for reflected self-evaluations and activation linearly increased with age for both reflected and direct self-evaluations. Longitudinal prediction analyses showed that positivity of self-evaluations predicted increases in self-concept clarity and less fear of negative evaluation one and two years later, highlighting the developmental benefits of acquiring a positive self-concept. Together, we show that adolescent self-development is characterized by dissociable neural patterns underlying self-evaluations in different domains, and from reflected and direct perspectives, confirming adolescence as a formative phase for developing a coherent and positive self-concept.