I have come across a lot of discussions where people end up calling belief a choice. Of course, I always ask them to believe that it's not, and they can't.
But it might help if I have a better psychological argument, or if there is psychological theory and evidence that says that belief is a choice, I would like that too. Theories could be about the nature of how beliefs are constructed in the brain, how the brain and body respond to stimuli which attack the beliefs, etc.
Clarification
I am not asking for opinion on free will or anything like that. I am asking for scientific theory and evidence, on the ability to actively change one's own beliefs, cognitive defense mechanisms against belief change, etc.