The Pathological Narcissism Inventory: Measurement Invariance Across Serbian and USA Samples and Further Validation

The aim of this research was To explore measurement invariance across samples from Serbia and the USA (Study 1) and to further validate the Serbian adaptation of the Pathological Narcissism Inventory - PNI (Study 2). The results supported the original seven-factor firstorder structure as well as the hierarchical structure of the PNI with Narcissistic grandiosity and vulnerability as the second-order factors. Further, scalar invariance between the two versions of the PM was achieved. Relations between Narcissistic grandiosity and vulnerability and other measures of grandiose and hypersensitive narcissism supported the validity of their scores. Among HEXACO traits, both Narcissistic grandiosity and vulnerability showed substantial negative correlations with Honesty-Humility. The main distinctions between the two aspects of narcissism lie in the positive relations with Neuroticism and negative relations with self-esteem, both of which are higher for Narcissistic vulnerability. The results support good psychometric properties of the PM scores and add to the PNI's cross-cultural validity.