Attachment to Parents, Differentiation of Self, and Marital Disillusionment in Japanese Newlyweds

Marital disillusionment is a key factor contributing to declines in relationship quality and marital instability, particularly in the early years of marriage. However, its underlying psychological mechanisms remain insufficiently understood. This study examined whether attachment to parents is directly associated with marital disillusionment and whether differentiation of self (DoS) mediates this relationship in Japanese newlyweds. A cross-sectional online survey was conducted with 1,049 participants aged 18–29 who had been married for less than 5 years. Attachment to parents, DoS, and marital disillusionment were assessed using validated self-report measures. Structural equation modeling indicated that parental attachment anxiety was directly and positively associated with marital disillusionment. Additionally, mediation analysis demonstrated that emotional cutoff, a key dimension of DoS, significantly mediated the relationship between attachment anxiety and marital disillusionment. These findings suggest that difficulties in regulating emotional closeness and distance may serve as a mechanism linking early attachment experiences to negative perceptions of marital relationships. Clinically, the results highlight the importance of addressing unresolved parental attachment issues and fostering healthier DoS in interventions targeting marital disillusionment.