The cold and formal is really hard. Personally, I think it is self-protection - compartmentalizing and putting up a wall. I mean, let's face it, their behaviour is pretty terrible, they must have to ring fence it, bury it or project outwards. And yes, as Flummoxed said, trying to create the illusion of control 'I am the sane, logical one here. NOTHING wrong with me'. Probably part of the same thing - I suspect that the coldness can sometimes be a sort of passive aggressive anger. They know they are the perpetrator of so much hurt, and somehow they double down with monstrous self-justification. Often they get kinda grandiose like this when there is OM/OW bolstering them up. In short - facade.