The aim of this work was to adapt and validate the Sibling Attachment Inventory (SAI) in Mexican young adults and analyze its psychometric properties. Using an Internet-based survey, data were collected from 307 (64.5% female) Mexican young adults university students (aged 18-30). Exploratory and confirmatory factor analyses were performed to determine the factor structure of the revised Mexican version of the Sibling Attachment Inventory (SAI-RMx). Convergent and predictive validity were verified by carrying out correlations with the parent form of the Inventory of Parent and Peer Attachment (IPPA), the Lifespan Sibling Relationship Scale (LSRS), the Satisfaction With Life Scale (SWLS), and the Rosenberg Self-Esteem Scale (RSE). Results indicated that the SAI-RMx presents good levels of internal consistency and a monodimensional structure, also providing evidence for convergent, predictive, and construct validity. Furthermore, secure attachments were linked with high levels of self-esteem, as well as with high levels of life satisfaction. The SAI-RMx is expected to be a reliable instrument for measuring the global level and the three components of secure attachment between siblings in the young adult's Mexican population.
Keywords: satisfaction with life; self-esteem; sibling attachment; sibling relationships; young adults.