[1][2] Biosocial theory also explains the shift from evolution to culture when it comes to gender and mate selection.
[3] M. M. Linehan wrote in her 1993 paper, Cognitive–Behavioral Treatment of Borderline Personality Disorder, that "the biosocial theory suggests that BPD is a disorder of self-regulation, and particularly of emotional regulation, which results from biological irregularities combined with certain dysfunctional environments, as well as from their interaction and transaction over time"[4] The biological part of the model involves the idea that emotional sensitivity is inborn.
It is the transaction between the biological and the social part, especially with invalidating environments, that brings problems.
According to a 1999 article published by McLean Hospital, DBT is based on a biosocial theory of personality functioning in which BPD is seen as a biological disorder of emotional regulation.
Characteristic behaviors and emotional experiences associated with BPD theoretically result from the expression of this biological dysfunction in a social environment experienced as invalidating by the borderline patient.