The relationship between intolerance of uncertainty and fear of missing out: Evidence from network analysis and a daily diary study

Intolerance of uncertainty (IU) and fear of missing out (FoMO) are common psychological vulnerabilities during emerging adulthood, yet their item-level organization and daily temporal associations remain underexplored. Study 1 ( N = 875) used item-level network analysis in an undergraduate sample to examine the conditional association structure of IU and FoMO. Study 2 ( N = 235) used a 14-day diary design and dynamic structural equation modeling to examine their within-person temporal associations at the construct level. In Study 1, IU and FoMO formed two communities with stronger within-community than cross-community connections. In Study 2, both constructs showed autoregressive continuity and positive bidirectional cross-lagged associations. Higher daily IU was associated with higher next-day FoMO, while higher daily FoMO was associated with higher next-day IU. Together, the findings describe complementary aspects of the IU-FoMO relationship: Study 1 identifies candidate item-level interface domains, whereas Study 2 independently shows temporal coupling between daily IU and daily FoMO at the construct level. These findings may inform future research and the development of interventions for uncertainty-related distress and socially specific missing-out concerns among college students.