This is a wonderful article on the Dunning-Kruger Effect.
It mentions Donald Rumsfeld's famous "unknown unknowns" which I thought, at the time, was quite profound. I don't like Mr Rumsfeld's politics, but I don't think he was stupid.
It is a mental discipline to be aware of your limitations and know that you don't know the answer to things. Without this awareness, it is very easy to reach the wrong conclusions about the answers we get to questions.
The Dunning-Kruger Effect can explain the cognitive dissonance that is required for religious belief. By substituting critical thinking on what is presented by an authority figure with "blind acceptance" may not be so wilfully blind, but more of a "built-in" blindness. Maybe a lot of the faithfull are simply, neurologically incapable of being aware of their own short-circuited logic.
(These are just notes for myself to work out something later)