What can one say about those who practice deliberate ignorance? They possess intellect, yet deliberatly refuse to use it for fear of what? The exposure to ideas that would create cognitive dissonance? Afraid of losing their authority?
I find the deliberately ignorant to be so far beyond the malediction of stupid that I know no name strong enough to match such degenerate thinking.
This is sort of a taboo topic. This crosses over the socio-religious and socio-political landscapes,...as well as, individuals who are susceptible to conspiracy theories. Cognitive dissonance certainly appears to be a psychological condition,...that may, in some cases, have some underlying neuro-anatomical foundations.
There is some neuroimaging studies to suggest that the amygdala of the aforementioned people may be significantly larger than that of others,...you mentioned fear,...the amygdala being "the fear center".
The prefrontal cortex, in part, is as we know, the part of the brain that also is responsible for cognitive empathy,...you mentioned living in a "bubble" and purposely limiting themselves to exposure to new ideas. Psychologically, one is solidifying their "personal truths" as "fact" and "wisdom",...and anything that challenges that with what they know is threatening to "their truth". So, as a means of creating a "safe space", they only associate with others with similar personal truths,...tribalistic behaviors. "Others" and "other ideas" become a threat. This significantly affects the cognitive empathy and an ability to understand different perspectives and contexts.
So, there is some similarity with some autism variants,...but I don't see a lot of autistics that present with the sorts of things you speak of. Granted, a few do. Perhaps, because many autistics tend to be more socially isolated for one reason or another,...and tend to be more independent thinkers.