Evidently, the emotional wounds go pretty deep, to the extent of delusion. Even basic facts are ignored, while random patterns are misinterpreted as "fact" or "evidence". I think it would be healthy to engage with people and groups and find out exactly why they are so vehemently distrustful of everything, even cold hard evidence. Of course, they don't see it and won't believe anything you or I say, but with time and persuasion, I think they'll see the bleeding obvious. Alain is spot on - these are otherwise intelligent people who somehow seem to shut down their logic when it comes to some matters.