Shared Fate in Adults Romantic Relationships

This pre-registration outlines a longitudinal investigation of shared fate in adult romantic relationships, defined as the perception that partners’ life outcomes are meaningfully intertwined. Grounded in interdependence theory and fitness interdependence theory, the project examines shared fate as a psychological mechanism through which romantic partners coordinate behavior, provide mutual support, and maintain relationship quality across time. Using a three-wave longitudinal dataset of U.S. adults in ongoing romantic relationships, the project consists of two complementary studies. Study 1 evaluates the psychometric properties of the Shared Fate Scale (SFS) in romantic relationships across a two-year period. Specifically, the study tests longitudinal measurement invariance (configural, metric, and scalar), internal reliability, and rank-order stability of perceived and emotional shared fate. It also examines whether shared fate reflects primarily stable individual differences or context-sensitive fluctuations using random-intercept modeling to separate between-person and within-person variance. Study 2 examines shared fate as a developmental process linking relationship duration to relationship quality. The study tests whether shared fate predicts positive and negative relationship quality at both the between-person and within-person levels and evaluates shared fate as a potential mediator of the association between relationship duration and relationship quality. Exploratory moderation analyses assess whether these associations differ by relationship status, age, gender, and exposure to stressful life events. All analyses will be conducted using structural equation modeling with robust maximum likelihood estimation and full-information maximum likelihood to address missing data. By integrating psychometric validation with longitudinal modeling of relational processes, the project aims to clarify whether shared fate functions as a stable relational resource and whether it contributes to changes in romantic relationship quality across adulthood.