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Does anyone know if there is some phenomenon that would explain this? Maybe I’m searching too hard for answers, but I guess I wish there was an explanation for why he seems to be immune from the parental alienation tactics that I could extrapolate and use to help get the hearts back from my other kids. I’m guessing it’s far more complicated than that and has roots going way back, but I still thought I’d ask.
Sorry you're going through this; it was one of my bigger fears as well.
I do think you're searching too hard for answers though; focus on what to do about it
first. "
Why" BPDers do the things they do are really an academic/psychological focus. If you're in the thick of it, your first priority should be countering the alienation attempts and behavior.
In addition to reading the books suggested, have you considered getting a T for the kids?
In my own case, so far I haven't seen any signs of alienation, though it's not for want of effort on the part of BPDxw. My kids seem resilient enough to ignore it for what it is, and make up their own minds about what is right and what is wrong, and who did or said what. Taking them to the T though has been beneficial - both for them and for me. In my own case, it helps assuage my worries of them suffering or developing some unhealthy coping mechanisms from the divorce, and also gives me the peace of mind that I have another adult who can help me out and (if necessary) testify in court on my behalf.