To fear or to rejoice: Social media mindsets and their relationships to social media engagement, perceived connectedness, fear of missing out and joy of missing out

• Introduces social media mindsets as predictors of FoMO and JoMO. • Agency mindset is negatively associated with FoMO and positively associated with JoMO, potentially through reduced passive social media engagement. • Valence mindset is positively associated with active social media engagement, yet also linked to heightened FoMO. • Perceived connectedness mediates between social media engagement patterns and psychological outcomes. • Digital life balance moderates the relationship between perceived connectedness and JoMO. As social media becomes ubiquitous, users exhibit contrasting psychological responses. Some experience the Fear of Missing Out (FoMO), whereas others feel the Joy of Missing Out (JoMO). However, existing research offers limited insights into why these divergent experiences occur, particularly regarding the role of users’ cognitive orientations in shaping digital experiences. Drawing on the Differential Susceptibility to Media Effects Model (DSMM), this study introduces the concept of social media mindsets to explain individual differences underlying FoMO and JoMO by examining how agency mindsets and valence mindsets influence psychological outcomes through engagement patterns and perceived connectedness. The findings revealed that stronger agency mindsets were associated with lower FoMO and higher JoMO, whereas stronger valence mindsets were paradoxically related to higher FoMO and lower JoMO. Active engagement was associated with greater perceived connectedness, which in turn related to reduced FoMO, while digital life balance moderated the link between perceived connectedness and JoMO. This study extends DSMM by incorporating social media mindsets as explanatory mechanisms for divergent user experiences, offering theoretical insights into why similar behaviors yield different psychological outcomes and providing practical guidance for fostering healthier digital engagement through adaptive mindsets and self-regulation.