A Dyadic Model of the Association Between Childhood Attachment Injuries and Marital Relationship Instability: The Mediating Roles of Interpersonal Emotion Regulation and Rejection Sensitivity

Abstract

This study aimed to test a dyadic model of the association between childhood attachment injuries and marital relationship instability through the mediating roles of interpersonal emotion regulation and rejection sensitivity among married couples in Tehran. This descriptive-correlational study employed dyadic structural equation modeling. The statistical population consisted of married couples residing in Tehran in 2026. A total of 300 couples, including 300 women and 300 men, yielding 600 participants, were selected through convenience sampling. Data were collected using the Childhood Attachment and Relational Trauma Screen, Interpersonal Emotion Regulation Questionnaire, Rejection Sensitivity Questionnaire, and Marital Instability Index. Data were analyzed using the Actor-Partner Interdependence Model and Actor-Partner Interdependence Mediation Model in SPSS version 29 and Mplus version 8.10. Indirect effects were examined using 5,000 bootstrap resamples. The structural model demonstrated satisfactory fit (χ²/df = 1.91, CFI = 0.954, TLI = 0.947, RMSEA = 0.039, SRMR = 0.041). Childhood attachment injuries negatively predicted interpersonal emotion regulation in women (β = -0.42) and men (β = -0.39) and positively predicted rejection sensitivity in women (β = 0.49) and men (β = 0.46). Direct actor effects of childhood attachment injuries on marital instability were significant for women (β = 0.18) and men (β = 0.16). Significant partner effects were also observed across the principal paths. Indirect effects through interpersonal emotion regulation and rejection sensitivity were significant for both spouses. The model explained 48% of the variance in women’s marital instability and 44% of the variance in men’s marital instability. Childhood attachment injuries were associated with marital instability through both actor and partner pathways, while interpersonal emotion regulation and rejection sensitivity played significant mediating roles. These findings indicate that marital instability is best understood as a dyadic process in which both developmental attachment histories and current emotional-interpersonal mechanisms contribute to relational instability.