Narcissist or narcissistic? Evaluation of the latent structure of narcissistic personality disorder

We investigated the latent structure of narcissistic personality disorder by comparing dimensional, hybrid, and categorical latent variable models, using confirmatory factor analysis (CFA), nonparametric and semiparametric factor analysis, and latent class analysis, respectively. We first explored these models in a clinical sample and then preregistered replication analyses in 4 additional data sets (with national, undergraduate, community, and mixed community/clinical samples) to test whether the best-fitting model would generalize across different data sets with different sample compositions. A 1-factor CFA outperformed categorical models in fit and reliability, suggesting the criteria do not serve to distinguish a narcissist class or subtypes; rather, a narcissistic dimension underlies the narcissistic personality disorder construct. The CFA also outperformed hybrid models, indicating that people fall within the same continuous distribution, rather than composing homogenous groups of relative severity (nonparametric factor analysis) or pulling apart into mixtures of discrete distributions (semiparametric factor analysis) along that spectrum.