A principal-components analysis of the Narcissistic Personality Inventory and further evidence of its construct validity.

TLDR

We examined the internal and external validity of the Narcissistic Personality Inventory (NPI). The authors conducted three studies: a large-scale internal structure analysis of the NPI with 1,018 participants, a construct validity assessment against observational and self‑report data with 57 participants, and a validity test using self and ideal self‑descriptions and Leary Interpersonal Check List congruency with 128 participants. Principal‑components analysis revealed a general narcissism construct and seven first‑order components (Authority, Exhibitionism, Superiority, Vanity, Exploitativeness, Entitlement, Self‑Sufficiency), and the subsequent studies supported the NPI’s construct validity for both the full scale and its component scales.

Abstract

We examined the internal and external validity of the Narcissistic Personality Inventory (NPI). Study 1 explored the internal structure of the NPI responses of 1,018 subjects. Using principal-components analysis, we analyzed the tetrachoric correlations among the NPI item responses and found evidence for a general construct of narcissism as well as seven first-order components, identified as Authority, Exhibitionism, Superiority, Vanity, Exploitativeness, Entitlement, and Self-Sufficiency. Study 2 explored the NPI's construct validity with respect to a variety of indexes derived from observational and self-report data in a sample of 57 subjects. Study 3 investigated the NPI's construct validity with respect to 128 subject's self and ideal self-descriptions, and their congruency, on the Leary Interpersonal Check List. The results from Studies 2 and 3 tend to support the construct validity of the full-scale NPI and its component scales.