Structural Equation Modeling of the Relationship Between Emotion Regulation Difficulties and Cloninger's Personality Traits with the Mediating Role of Cognitive Flexibility in Psychology Students at Tehran Islamic Azad University of Medical Sciences

Background Previous studies have shown that emotion regulation problems are associated with personality dimensions such as harm avoidance and self-direction, but the precise mechanisms of these relationships have been less explored. This study focuses on the two components of emotion suppression and reappraisal to analyze their direct and indirect effects on Cloninger's personality traits in psychology students. Methods This study utilized a descriptive correlational design and included 300 psychology students from Islamic Azad University using accessible sampling. Participants completed the Difficulty in Emotion Regulation(DERS), Cloninger Temperament Inventory(TCI), and Cognitive Flexibility(CFS) questionnaires anonymously. The data was analyzed using structural equation modeling (SEM) in PLS software, evaluating fit indices(CFI, TLI, RMSEA), and the bootstrap method for mediation. Results Direct findings revealed that emotion suppression had a significant impact on reducing reward dependence (p < 0.001) and self-direction (p = 0.03), while reappraisal was linked to an increase in harm avoidance (p = 0.043) and self-effacement (p = 0.003). On an indirect level, emotion suppression significantly influenced novelty seeking (p = 0.003), harm avoidance (p < 0.001), perseverance (p = 0.015), cooperation (p = 0.001), and self-direction (p < 0.001), but did not show a confirmed relationship with self-effacement (p = 0.274). Similarly, reappraisal had an indirect effect on all personality dimensions except for self-effacement (p = 0.262). These findings support the hypothesis of both direct and indirect effects of emotion regulation on personality traits, with the exception of self-effacement, which did not play a role in the indirect relationships. Conclusion The components of emotion suppression and reappraisal independently have direct and indirect effects on personality dimensions such as reward dependence, self-direction, harm avoidance, and self-transcendence. However, self-transcendence is only affected at the direct level. These findings highlight the significant role of emotion regulation mechanisms in shaping personality models.