DBT is anchored in a theory of BPD that prompts clinicians to focus on emotions and emotion regulation in treatment. According to the biosocial theory, BPD is primarily a disorder of emotional dysregulation such that the individuals with BPD have (a) heightened emotional sensitivity, (b) inability to regulate intense emotional responses, and (c) slow return to emotional baseline. In addition to this, Linehan proposed that a biologically vulnerable child transacts with an invalidating rearing environment. Such an environment is characterized by intolerance towards the expression of private emotional experiences and intermittent reinforcement of extreme expressions of emotion. The child does not learn how to understand, label, regulate, or tolerate
