Psychometric Evaluation of a Bulgarian Version of the Narcissistic Personality Inventory NPI-40 Cover Image

Психометрична оценка на българска версия на Въпросника за нарцистична личност NPI-40
Psychometric Evaluation of a Bulgarian Version of the Narcissistic Personality Inventory NPI-40

Author(s): Valeri Todorov, Plamen Petkov
Subject(s): Social Sciences, Psychology, Personality Psychology
Published by: ЮГОЗАПАДЕН УНИВЕРСИТЕТ »НЕОФИТ РИЛСКИ«
Keywords: Narcissistic Personality Inventory–40 (NPI‑ 40); Bulgarian adaptation; psychometric validation; confirmatory factor analysis; convergent validity; regulatory focus

Summary/Abstract: This study reports the translation, adaptation, and psychometric evaluation of a Bulgarian version of the Narcissistic Personality Inventory (NPI-40). Following independent forward and backward translations and expert review, the instrument was administered online to 664 Bulgarian adults (77.7% women; mean age, M = 38.0, SD = 11.2). Participants also completed the Regulatory Focus Questionnaire to assess the convergent validity of the results. Classical test theory indices demonstrated high internal consistency for the total NPI-40 score (α = .85; ω = .85), though two subscales (“Self-sufficiency” and “Entitlement”) yielded lower reliabilities (α < .50). Correlational analyses supported convergent validity, revealing positive associations between total and subscale NPI-40 scores and the Promotion focus, and negative associations with the Prevention focus. Confirmatory factor analyses compared correlated seven-factor, hierarchical, and bifactor models. The bifactor solution demonstrated superior fit (CFI = .988; RMSEA = .020), confirming a strong general narcissism factor alongside specific dimensions. These findings suggest that the proposed Bulgarian version of the NPI-40 is a reliable and valid measure of trait narcissism in nonclinical samples. Thеsе results facilitate the use of the NPI-40 in Bulgarian language research across various psychological domains, including personality, interpersonal relationships, leadership, and organizational behavior.

  • Issue Year: 18/2025
  • Issue No: 2
  • Page Range: 560-582
  • Page Count: 23
  • Language: Bulgarian
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