The Role of Diagnostic Models in Prejudice Toward People With Borderline Personality Disorder: An Experimental Investigation.

We tested whether dimensional personality disorder models such as the Alternative Model for Personality Disorders (AMPD) cause less prejudice toward people with borderline personality disorder (BPD) than categorical models, and we sought to identify the mechanisms underpinning this reduction in prejudice. Undergraduate psychology students (n = 183) were randomly assigned to one of three conditions (AMPD, categorical, control) and given descriptive information about BPD. Participants in the AMPD and categorical conditions also received a presentation about their respective BPD diagnostic criteria. Students in all conditions then completed a survey assessing their prejudice toward people with BPD. There was no difference between conditions on overall prejudice toward people with BPD. However, the AMPD increased continuum beliefs and decreased categorical beliefs, and these, in turn, affected perceptions of people with BPD as ingroup members, which indirectly reduced prejudice. We have identified pathways through which the AMPD indirectly reduces prejudice toward people with BPD.