Abstract
<p>Introduction: Behavioral and affective instability in interpersonal interactions, a common struggle for individuals with personality dysfunction, poses a significant challenge for clinicians and serves as a major obstacle preventing them from making progress in their lives. This study examined the relationship between interpersonal variability and personality functioning using multilevel modeling, as well as the unique explanatory power of interpersonal variability beyond its mean-level. Methods: This study combines a longitudinal approach with experience sampling features, collecting monthly data from 342 adults over six months. Personality functioning was assessed with the Level of Personality Functioning Scale Self-Report (LPFS-SR), and interpersonal behaviors (submissive, quarrelsome), perception of other’s behavior, and affects (positive and negative) were assessed with self-report measures.Results: Variability in quarrelsome behavior, perception of other's behavior, and negative affect were significantly associated with personality functioning at within-person and between-person levels. However, the relationships between variability in submissive behavior, positive affect, and personality functioning diverged at each level. Moreover, variability in submissive behavior and perception of other's behavior accounted for additional variance beyond mean-levels. Conclusion: Results suggest the importance of considering not only the degree but also the temporal variability of interpersonal behaviors and affects in constructing personalized models of personality dysfunction.</p>