Theoretical and empirical research has linked poor emotion regulation abilities with dysfunctional frontolimbic circuitry. Consistent with this, research on borderline personality disorder (BPD) finds that frontolimbic dysfunction is a predominant neural substrate underlying the disorder. Emotion regulation is profoundly compromised in BPD. However, BPD is also associated with broad impairment across multiple domains, including impulse control, interpersonal relationships, and cognitive functioning. To date, BPD research has focused largely on single areas of dysfunction, failing to account for overlap at either the biological or behavioral levels of analysis. We examine the literature on frontolimbic dysfunction in BPD within the context of Coan's social baseline theory. Social baseline theory proposes that healthy human functioning is dependent upon adequate social support and that, at baseline, biological systems are adapted to operate interdependently rather than independently. The social baseline perspective is particularly useful for understanding borderline personality development because the impulsive and emotionally dysregulated behaviors common among those with BPD occur almost invariably within an interpersonal context. We discuss clinical and research implications of this work.