Introducing a short form version of the Scale for Interpersonal Behaviour (s-SIB) for use in Italy

A short form version of the Scale for Interpersonal Behaviour (s-SIB), based on analyses of a sample of Italian students (N=1073), is presented: it comprises 25 items (50% of the original item pool), each rated separately for difficulty and distress in assertiveness. Using the multiple group method of confirmatory analysis, the four distress and performance factors (Negative assertion, Personal limitations, Initiating assertiveness and Positive assertion) were each replicated. The corresponding scales were internally consistent and showed predicted patterns of correlation with measures assessing irrational fears, sex roles, neuroticism, extraversion, social conformity and self-esteem. One interesting and consistent sex difference was noted, namely that all measures of distress in assertiveness (including the overall scale, but excluding the Negative assertion subscale) were significantly negatively associated with femininity in males, but not in females. This sex difference did not emerge in a previous study using the original SIB with students from Spain. The s-SIB is recommended as a reliable and valid functional equivalent to the 50 item SIB when the clinical and/or research context does not adequately permit the application of the original scale.