This study assessed the structural relations between borderline personality disorder (BPD) features and purported etiological correlates. Approximately 5,000 18-year-old nonclinical young adults were screened for BPD features, and 2 cohorts of participants (total N= 421; approximately one half of whom endorsed significant borderline features) completed the laboratory phase of the study. Measures included self-report and interview-based assessments of BPD psychopathology, personality, psychopathology in biological parents, and childhood physical and sexual abuse. Significant relations between BPD features and purported etiological correlates of BPD were found. A multivariate model that included parental psychopathology, childhood abuse, and personality factors provided an adequate fit to the data and supported the contention that the personality traits disinhibition and negative affectivity underlie BPD features.(PsycInfo Database Record (c) 2022 APA, all rights reserved)