Most people who are not genius do consider highly intelligent individuals to be strange, insane, or a little weird.
Very smart people tend to be different and very independent. They do not fall into a cookie cutter idea of a normal person. That’s not a bad thing but it does color the view of the average Joe.
Funny coincidence - this just showed up on my FB wall:
“The thing about smart people is that they seem like crazy people to dumb people.”
I remember reading some, years back, of a study involving a group of teens who were stereotypical nerdy braniacs. In mapping the subjects’ brain activity, the researchers found that their brains “fired up” in very unexpected ways. The part of the brain that should have been firing in social situations was just not involved.
Sorry, I am probably not describing this well, as this has been quite a while ago. Basically, the implications were that the academically brilliant nerdy kids just did not function well in social interactions, hence the strangeness factor you allude to.
You said it best!
Just as tribal members feared shamans, people who don’t understand will be suspicious, fearful or critical.