Linehan’s (1993) biosocial theory of borderline personality disorder (BPD) posits that (1) behavioral dysregulation results from emotion dysregulation, and (2) emotion dysregulation is due, in part, to attentional biases. The primary goal of this study was to examine these tenets in young adult women with BPD and control subjects. College female students were screened for BPD symptoms to determine eligibility for the laboratory portion of the study. A total of 84 women completed the study, which included a series of mood manipulations, several tasks assessing behavioral dysregulation, and a measure of attentional bias. Psychophysiolgoical data (heart rate and skin conductance) were also collected as objective indices of emotional regulation and arousal. Analyses indicated that the groups (BPD vs. control) differed meaningfully and as expected on several self-report measures associated with BPD; however, there were relatively few differences on objective measures of emotional and behavioral dysregulation. There were no significant group differences in attentional biases. The present results provide limited support for the biosocial theory in nonclinical young adults.