IMO, the short answer is that they believe it. I have not, however, read Captives of a concept, nor Steve Hassan’s book, but from what I have read, I think he would agree.
I agree on the comments of major cognitive dissidence too. In short, I think they are a group that all have Narcissistic personality disorder, that have a natural ability to manipulate (using propaganda, logical fallacies, etc.) and would deny any reality put before them.
Chris Hedges has observed the concept that many “people are not moved by facts or reason, but by the skillful manipulation of emotion.” After all, that is the cause of so much of the bad in the world. GB included.
HBH