Abstract
Grounded in social penetration theory and social capital theory, this study aims to investigate how social media self-disclosure influences bridging and bonding online social capital, and how these in turn affect users' loneliness and online interpersonal trust. A moderated mediation model was proposed and tested using cross-sectional survey data collected from 1519 Chinese netizens. Regression analyses revealed that self-disclosure on social media positively predicted both types of online social capital. Bridging social capital mediated the relationship between self-disclosure and reduced loneliness, while bonding social capital mediated the link between self-disclosure and enhanced online interpersonal trust. Moreover, agreeableness moderated the effect of self-disclosure on bonding social capital. These findings enrich the theoretical understanding of online self-disclosure and reveal the underlying motivations for users to disclose personal information on social media, even in the context of the privacy paradox.