From Digital Exposure to Identity Process: An Integrative Theoretical Review of Social Media Affordances, Meaning‐System Congruence, and Distress in Adolescence and Emerging Adulthood

INTRODUCTION: Research on digital media and mental health often treats exposure duration as the primary explanatory variable. This approach is poorly suited to identity development, because the same amount of social media use can involve qualitatively different practices, from authentic self-expression to social comparison and audience management. This integrative theoretical review concerns adolescence (approximately ages 12-18) and emerging adulthood (approximately 18-25), the developmental periods in which identity exploration is most active and in which social media use is most intensive. METHODS: We synthesize four literatures that have developed largely in parallel (neo-Eriksonian identity-process research, self-presentation and self-discrepancy theory, social-comparison research on social media, and meaning-making theory) together with affordance-based accounts of digital environments. RESULTS: We use that synthesis to develop a developmental framework that shifts the unit of analysis from digital exposure to identity process. The framework specifies three proximal mechanisms through which social media practices may shape identity: exploration regulation, cross-context self-discrepancy, and externalized self-evaluation. Each mechanism is anchored in a normative developmental task of these periods: widening and then consolidating the field of identity alternatives, integrating an increasingly differentiated self across contexts, and shifting the basis of self-evaluation from external approval toward internalized standards. Meaning-system congruence, the perceived compatibility between identity-relevant digital experiences and internalized cultural, spiritual, relational, and moral frameworks, is proposed as a moderator rather than a direct cause: clear but flexible meaning systems are expected to support integration, whereas perceived conflict may intensify self-discrepancy and reconsideration. Offline enactment and social connectedness are proposed as protective processes that allow commitments to be tested outside platform metrics. Throughout, we distinguish established associations, indirect evidence, and untested propositions, and we translate each proposition into measurement strategies and longitudinal and experimental designs with explicit falsification criteria. CONCLUSIONS: Clinically, the framework supports contextual inquiry into digital practices and identity conflict without pathologizing normative exploration. The review is intended to organize a fragmented evidence base into a discriminating and testable developmental research program.