Persons with Borderline Personality Disorder (BPD) often describe difficulty making and maintaining healthy relationships. Often, the relationships they do have are characterized by conflict. A key component of Dialectical Behavior Therapy (DBT) is interpersonal skills training, to correct assumed deficits.
What exactly are these deficits? What tasks do those with BPD struggle with? By identifying specific, common deficits, treatment can be better focused and efficient. One recent study administered several measures designed to assess for specific deficits to persons with BPD, persons with avoidant personality disorder (APD), and a control group. There were several findings possibly relevant for BPD treatment.
First, persons with BPD identified anger in others at a lower threshold than persons in either other group. In contrast, there were no significant differences in how the three groups identified happiness in others. This is consistent with the notion that persons with BPD are more sensitive in "social threat identification." That is, they have a bias towards identifying anger. They may mistake minor annoyance for something greater, leading to a stronger emotional response than is justified. Or, they may identify someone as being angry when they are not, leading to unnecessary conflict.
Second, persons with BPD had a greatest difficulty identifying their own emotions. Dialectical Behavior Therapy addresses this deficit through the framework of mindfulness. Persons are asked to practice observing their mental states, and then describing them. This includes making accurate assessments of emotional states. The theory is that, over time, persons will become better at recognizing their emotional states (and less self-critical about them).
Third, it is not surprising that both of the above findings were associated with greater levels of interpersonal difficulty.