I think you are both right.
We all have these archetypes that exist within the unconcious mind. Events in life trigger them and they play out how we have been conditioned to relate to them. The conditioning never ends though and in our relationship we are further conditioned.
I believe this to be true Blimblam, I think we are all capable of these different behaviours and our life experiences direct whether they get played out. This belief gives me empathy for the pwBPD because I see that we all have these traits. Why didn't I become BPD while he did? It wasn't a choice, it was probably many factors including genetics and the severity of abuse that he experienced growing up.
I was obviously codependent in this r/s with my exh but am I codependent in every r/s, every friendship, with my kids? No. I think that this r/s triggered my codependency. Why? For me it was b/c it brought up a lot of my FOO issues. Did it cause my codependency? No, I think I was always vulnerable to it.
Funny thing about codependency, my mother joined a 12 step codependent group a couple decades ago and then eventually she ran the group. Now after all this learning about BPD I would say she is closer to BPD than being a codependent! It is my father who is the codependent in their r/s (and funny enough he is also running a men's group for codependency!) I asked my T how it can be that my mother has been involved in this 12-step program for all these years and she is still in complete denial about her mental illness, her compulsions (she's an alcoholic), her dysfunctional behaviours (she's really nuts and we've been estranged now for 5 yrs). She says that some people try to spiritually by-pass the work they need to do.
I find the spiritually bypass the work they need to do thing to be extremely common. Extremely! I find my parents to take the ayn rand brand of spiritually bypassing the work they need to do. I got heavily involved in groups focused on saving the rain forest and found many many of the people involved were doing the same thing. I think narcissism is often confused with spirituality and it takes many shapes and forms.