It is entirely possible we have been thinking about this in a way which is unproductive, or not thinking about it at all. Either way a different perspective certainly can’t do any harm. I have read and heard quite a few different numbers quoted, percentages of the number of people who suffer from BPD who have suffered trauma, one of the things which really caught my attention about this specific talk is how Dr van der Kolk points out that we need no longer speculate or debate. He succinctly points out that with the body of research on this subject we can be assured that the correlation is indicative of causation.
In my personal experience with people who suffer from BPD the trauma has been present in their lives every time. A very interesting talk indeed.