Differentiation of Self, Attachment Experiences, and Dyadic Adjustment: An APIM Approach With Spanish‐Speaking Couples

Romantic relationships are a cornerstone of adult life, profoundly influencing individuals' overall well-being. When these relationships become distressed, the consequences often extend beyond the couple, affecting families and the communities. Despite growing research on factors associated with couple relationships, much of the existing evidence is limited to the US and English-speaking populations, underscoring the need for studies in other contexts, such as Spanish-speaking couples. Our sample included 68 heterosexual, Spanish-speaking couples from Argentina, Costa Rica, Guatemala, Mexico, and Spain. We examined how differentiation of self and attachment experiences uniquely predicted four dimensions of dyadic adjustment: satisfaction, consensus, cohesion, and affectional expression. We utilized an Actor-Partner Interdependence Model (APIM), complemented by a Monte Carlo simulation-based power sensitivity analysis. Overall, higher differentiation (i.e., lower emotional reactivity and cutoff) was associated with greater consensus and affectional expression, while higher attachment anxiety and avoidance were linked to decreased satisfaction, cohesion, and affectional expression. Our findings emphasize the complex interplay between romantic partners' differentiation of self, attachment experiences, and relationship well-being. Findings suggest that clinical interventions aimed at enhancing differentiation of self and addressing attachment insecurity may improve relationship functioning. Future research should explore these dynamics in more diverse samples and cultural contexts to further understand the nuances of the current findings and refine clinical interventions for couples.