Yes and no. It’s a loyalty test and a demonstration of power. The more obviously stupid the bullshit that you can get your followers to believe, the more powerful you must be, and the followers need a powerful daddy leader, so they buy it. It’s also a way to signal that you’re part of the in-group to others in the group.
So they believe it, without concept of objective truth even being involved.
Yep. I chose the words of that comment carefully to say he acted with integrity, not has integrity.