Iranian Association for Intelligence and Talent Studies International Journal of Education and Cognitive Sciences 3041-8828 7 September 2026 2026 09 01 Designing a Model of Fear of Missing Out Based on Identity Styles with the Mediating Role of Behavioral Brain Systems in Female University Students Using Cyberspace Designing a Model of Fear of Missing Out Based on Identity Styles with the Mediating Role of Behavioral Brain Systems in Female University Students Using Cyberspace 1 10 10.61838/kman.ijecs.353 EN Journal Article 2025 12 06 <p><strong>Purpose: </strong>The present study aimed to design and test a causal model of fear of missing out (FoMO) based on identity styles with the mediating role of behavioral brain systems among female university students.</p> <p><strong>Methods and Materials: </strong>This study employed a descriptive-correlational design within the framework of structural equation modeling (SEM). The statistical population consisted of undergraduate female students at Islamic Azad University, Arak Branch, during the 2025–2026 academic year. A sample of 224 participants was selected using convenience sampling. Data were collected using three standardized instruments: the Identity Style Inventory, the Behavioral Inhibition/Behavioral Activation System (BIS/BAS) scales, and the FoMO scale. Data analysis was conducted using SPSS version 27 and AMOS version 24. Assumptions of normality, linearity, independence of errors, and absence of multicollinearity were confirmed prior to model testing.</p> <p><strong>Findings: </strong>The results indicated that the proposed model demonstrated an acceptable fit (χ²/df &lt; 3, CFI &gt; 0.90, IFI &gt; 0.90, RMSEA &lt; 0.08). Identity cohesion showed a significant negative direct relationship with FoMO (β = -0.21, p &lt; 0.01) and a significant relationship with both behavioral inhibition (β = -0.20, p &lt; 0.01) and behavioral activation (β = 0.31, p &lt; 0.01). Identity confusion showed a significant positive relationship with FoMO (β = 0.29, p &lt; 0.01) and behavioral inhibition (β = 0.42, p &lt; 0.01), and a significant negative relationship with behavioral activation (β = -0.22, p &lt; 0.01). Indirect effects analysis revealed that behavioral brain systems significantly mediated the relationship between identity styles and FoMO, with all mediating paths significant at the 95% confidence level.</p> <p><strong>Conclusion: </strong>The findings confirm the significant role of identity styles and behavioral brain systems in explaining FoMO, highlighting that cohesive identity acts as a protective factor while identity confusion increases vulnerability, with behavioral inhibition and activation systems functioning as key mediating mechanisms.</p> https://journalecs.com/index.php/ecs/article/download/353/313