Validation and Measurement Invariance across Gender and Age of the Italian Interpersonal Acceptance-Rejection Loneliness Scale

The Interpersonal Acceptance-Rejection Loneliness Scale (IPARLS) is a self-report measure recently developed to measure the feeling of sadness resulting from the perception of the absence of adequate intimate or social interpersonal relationships and to overcome some limitations of the existing loneliness scales. The present study evaluates the psychometric properties of the Italian version of the IPARLS, latent dimensionality, reliability, validity, and tests the measurement invariance of the scale across gender and age. The scale was administered to a sample of 688 Italian adults (19–69 years; 351 females, 337 males). Results confirmed the uni-dimensionality of the scale and showed that it is reliable, valid and fully invariant as a function of gender and age. Moreover, data showed that only for males, loneliness is negatively associated with ageing. The IPARLS scale is confirmed to be a valid tool for investigating loneliness in the life cycle both from a clinical and research point of view.