Self-other agreement in the assessment of maladaptive personality traits.

Introduction: Integrating self- and other-reports allows gaining complementary information while assessing personality traits, thus leading to more reliable and generalizable previsions in relation to individuals' future behaviors. The current study explored self-other agreement in the assessment of maladaptive personality traits in an Italian community sample. Method: One-hundred and sixty individuals (80 targets and 80 informants) entered the study. Informants were spouse/life partners, dating partners, family members, and friends. Targets completed the Personality Inventory for DSM-5 (PID-5; Krueger et al., 2012), a self-report measure assessing the DSM-5 Section III dimensional personality traits, whereas informants filled-in the Personality Inventory for DSM-5-Informant Form (PID-5-IRF; Markon et al., 2013), the informant- report version of the PID-5. Data collection was performed through two different online surveys. Results: In the whole sample, self-other agreement was moderate (domains: mean r=.39; facets: mean r=.35). Correlations between the degree of self-other agreement, duration and perceived closeness of acquaintanceship was almost negligible. Self-other agreement was higher when informants were romantic partners (spouse/life or dating partners) than when they were family members or friends. Conclusions: Present findings outline the implications of integrating self- and other-report information in the assessment of maladaptive personality traits and tentatively suggest that self- other agreement might vary according to the type of informant. Reports of knowledgeable others represent a particularly valuable source of information, which may inform the assessment and diagnosis of Personality disorders (PDs). Indeed, self-reports of individuals with PDs are often unreliable or unobtainable due to the lack of insight typical of personality pathology. Future studies also on clinical samples, with multiple informants (including clinicians) are highly encouraged.