Measuring the quality of the sibling relationship during middle childhood: The psychometric properties of the Sibling Relationship Inventory

To address a significant gap in the literature on sibling relationships, the present study examined the psychometric properties of the Sibling Relationship Inventory (SRI) in an Italian sample. The study had three main aims: (i) to investigate the factorial structure of the SRI; (ii) to evaluate the invariance of the SRI's factorial structure across birth order; and (iii) to test the SRI's validity. To this end 385 children, 213 first-borns and 172 second-borns (aged 6 to 12) were recruited. Confirmatory factor analyses showed a three-factor structure identical to that reported by the authors of the SRI. Critically, the SRI structure was stable when first- and second-borns were considered separately. Overall, the Italian version of the SRI showed good psychometric properties.