How digitally-mediated interactions influence the psychological foundations of civic engagement: Evidence from urban water governance in China

Citizen participation has emerged as critical to urban environmental governance, yet the micro-level mechanisms linking institutional trust to civic engagement remain underspecified. This study reconceptualizes institutional trust as a heuristic cognitive mechanism that shapes environmental behavior under uncertainty and bounded rationality. We ask: How does institutional trust activate citizens' participation in urban water governance? Drawing on integrated survey and online participation data from Chinese cities, we develop and test a behavioral framework connecting institutional trust, personal norms, outcome awareness, perceived behavioral control, and public action. Our findings reveal that trust operates through dual pathways: directly enhancing participation while strengthening personal norms and perceived efficacy. Outcome awareness and behavioral control serve as key moderating mechanisms, with stronger effects among low-trust citizens. This study advances three contributions: a micro-foundational framework unpacking psychological processes linking trust to action; evidence that local government responsiveness enhances differentiated trust structures; and demonstration of how individual trust aggregates into collective environmental action. These findings offer actionable insights for designing trust-responsive participatory policies that account for citizen heterogeneity and enhance urban governance effectiveness.