How does borderline personality disorder develop? We all know the nature vs nurture debate. “This again??” But research continues to uncover the important roles of both genes and environment for many physical and mental health difficulties. The development of borderline personality disorder also includes these components.
Marsha Linehan’s biosocial model lines up with this perspective to describe two main factors at play. First, we are all born with a varying degree of emotional awareness, responding, and emotional sensitivity. This is part of temperament, our genetically endowed degree of emotional responding.
Second, we all have different environmental experiences and learning histories. We all get raised in some environment, for better or worse. Those environments have varying levels of support, engagement, or encouragement.
Linehan’s model asserts that high emotional sensitivity in children (nature/genetics) interacts with environmental factors to lead to the development of borderline personality disorder. Fruzzetti’s transactional model later described dismissive or highly critical parenting styles as a key environmental factor. Repeated childhood trauma also appears to be a risk factor.
Constant invalidation of emotional experience and behaviors appears to interfere with developing a natural sense of what and how much emotion is appropriate for which situations. Developing individuals get confusing messages on “the correct” emotions to experience or how to express them effectively. The result is difficult patterns of regulating an already-high degree of emotion that appear highly inconsistent, erratic, or maladaptive.
This is definitely a sad process to hear about. We can’t do anything about genetics (at least not yet?). And researchers recommend not expressing blame to parents or caregivers. They emphasize using practical methods to help individuals find adaptive ways to regulate emotion to improve lives now. Luckily that is possible for borderline personality disorder. Good trainings for how to help are out there (e.g., with dialectical behavior therapy, DBT).
The development of borderline personality disorder is very interesting but also very sad. But there is an upside understanding this development: It helps us build better therapist resources to help.
