Capturing between- and within-person variability of borderline traits in youth from a developmentally sensitive situational judgment perspective

The significance of early maladaptive traits for understanding the roots of borderline personality disorder (BPD) is increasingly endorsed. Given the interpersonal nature of BPD and fluctuations in phenotypic symptomatology, this study aims to test the assumption that a situation-contingent contextualized assessment of borderline traits is a viable avenue to more fully capture the way underlying traits are reflected in socioaffective behavior that occurs in age-relevant situations. We aimed to explore the extent to which the variability on these responses represents a meaningful construct for understanding the clinical richness of BPD. Toward this end, a contextualized measure of DSM-5 BPD traits was developed along a situational judgment test (SJT) format, allowing us to explore both between-person and within-person variability in a more economic format than repeated measurement does. Examination of the psychometric properties of the SJT revealed distinctive correlational patterns of the situation-based traits with symptom scales of a youth BPD measure, but also indicated that for certain traits consistency in trait level across different situations is more maladaptive, whereas for other traits a greater degree of variability in trait expression is more maladaptive. Overall, this work could set the stage for further research on the potential of SJTs for understanding personality vulnerabilities both at the dispositional and the dynamic level.