Can the experts please talk about the most typical causes of borderline personality disorder (bpd)?

My opinion only: I've come to believe that environmental forces play the largest role. This includes the family of origin home, the neighborhood, the culture, national & even world events. Humans do best when they have reason to trust and have confidence in all of those things. So, until we all have valid reasons to trust, we will suffer from painful, shifting - even explosive, intense but insubstantial lives.

BPD etiology: Biological (Genetics) & Environmental. Genetic predisposition is important, compounded by environmental factors such as faulty or poor parenting or early traumas.