Validation and Reliability of the Negative Interaction Scale for Couple Relationships in Peru: A Bayesian Confirmatory Factor Analysis Approach

This study focuses on validating a Negative Interaction Scale using a Bayesian approach for confirmatory factor analysis. Considering the significant impact of negative interactions on couple relationships, both in terms of satisfaction and the mental and physical health of individuals, the aim was to provide a reliable and precise tool for measuring these behaviors in a specific cultural context, such as that of young and adult individuals in Peru. A non-probabilistic convenience sampling design was used, involving 313 participants, predominantly women, and a majority identifying as heterosexual. The average age was around 26 years, encompassing various types of couple relationships. The Negative Interaction Scale (NIS-5) and the Peruvian version of the Relationship Assessment Scale (RAS) were employed for data collection, using Bayesian statistical tools for analysis, particularly Bayesian confirmatory factor analysis (BCFA), offering advantages in flexibility, precision, and the evaluation of the proposed unidimensional structure. The NIS-5 demonstrated a unidimensional structure with excellent fit indices, moderate to strong factor loadings, and good internal consistency, supported by an omega reliability coefficient of 0.836. These results validate the unifactorial structure of the NIS-5, reflecting that negative interaction can be globally and uniquely interpreted within the study context. The study confirms the validity and reliability of the NIS-5 as an instrument for measuring negative interaction in couple relationships in Peru. It highlights the importance of considering negative interaction to improve relationship quality and suggests the implementation of programs or theoretical models to promote healthier relationships.