The Total Score of the Level of Personality Functioning Scale Is Empirically and Theoretically Well-Justified: A Reply to Zavlis (2025)

In that paper, we examined the empirical convergence between Kernberg's model of personality organization (Kernberg and Caligor 2005) and the Alternative DSM-5 Model for Personality Disorders (AMPD; American Psychiatric Association 2013), including the constructs of personality functioning (PF; Bender et al. 2011) and pathological personality traits. Using exploratory bifactor models, we found that measures of Kernberg's model and the AMPD strongly converged regarding both general and specific personality pathology. Zavlis (2025) criticized our methodological approach, arguing it rests on the “implicit assumption” that PF is a “unitary entity.” He conducted secondary analyses of our published data to test whether PF “is truly unitary” and concluded that PF “is better understood both theoretically and psychometrically in terms of two distinct domains.”