Borderline personality features and emotional reactivity: the mediating role of interpersonal vulnerabilities.

BACKGROUND AND OBJECTIVES The purpose of this study was to examine the mediating role of interpersonal vulnerabilities in the association of borderline personality (BP) features with emotional reactivity to an interpersonal stressor. METHODS For this study, female university students with high (N = 23), mid (N = 23), and low (N = 22) BP features completed the Inventory of Interpersonal Problems-Personality Disorders-25 (IIP-PD-25). Self-reported emotions, skin conductance responses (SCRs), interbeat intervals, and heart rate variability measured emotional reactivity to a social rejection stressor. RESULTS BP features were positively associated with interpersonal dysfunction and predicted greater SCR reactivity and self-reported emotional reactivity. Interpersonal dysfunction mediated the association between BP features and physiological (SCRs), but not self-reported, emotional reactivity. In particular, scores on the interpersonal ambivalence subscale of the IIP-PD-25 mediated the association of BP features with SCR reactivity. LIMITATIONS This study examined BP features in a non-clinical sample, and relied on a relatively small sample. Furthermore, the design of the present study does not capture the potential transaction between interpersonal vulnerabilities and emotional dysfunction. CONCLUSIONS The findings of this study illuminate one potential mechanism underlying the heightened reactivity of persons with BP features to rejection, suggesting that interpersonal ambivalence plays a particularly important role in physiological reactivity.