The Narcissistic Grandiosity Scale and Narcissistic Vulnerability Scale: Testing their Convergent Validity, Factor Structure, and Measurement Invariance Across Gender/Sex among Canadian Adults

The 7-item Narcissistic Grandiosity Scale (NGS-7) and 11-item Narcissistic Vulnerability Scale (NVS-11) are two efficient and flexible measures of grandiose and vulnerable narcissism. Both scales demonstrate evidence of convergent, discriminant, and criterion validity, but their factor structure and gender/sex-based measurement invariance have received less attention. In addition, their relationships with the HEXACO (Honesty-humility, Emotionality, eXtraversion, Agreeableness, Conscientiousness, and Openness) have rarely been examined. Using a large sample of Canadian adults (N = 1712) we evaluated the convergent validity, factor structure, and gender/sex-based measurement invariance of the NGS-7 and NVS-11. Confirmatory factor analysis revealed that a one-factor model was a poor fit for both the NGS-7 and NVS-11. Modifications did not substantially improve fit for the NVS-11. However, removing one NGS-7 item (“authoritative”) led to much greater fit, and the revised 6-item NGS-6R demonstrated configural, metric, scalar, and residual invariance between men/non-binary and women. The NGS-6R was strongly associated with honesty-humility (r = -.42) and extraversion (r = .28), and uniquely associated with the facet of modesty. In summary, the unidimensionality of the NGS-7 and NVS-11 were not supported. However, the revised NGS-6R demonstrated evidence of unidimensionality, gender/sex-based invariance, and convergent validity. The NVS-11 may require revision, but the NGS-6R appears to be a robust measure of narcissistic grandiosity.