Truly, an interesting topic but I think one aspect is mostly missing by now, and that's psychological preposition.
I cannot say this for mathematicians or scientists in general, but for other professional groups. There are studies showing i.e. a connection between psychopathic tendencies and business executives, or aggressive or even sadistic tendencies and surgeons. Recently I read about a study researching esoteric beliefs in professional groups. Outcome: musicians and artists in general tend to esotericism, lawyers hate it!
To me it seems not unlikely that this goes for many areas. As a scientist you need the intrinsic drive to question basically everything and you need the mental capability to see structures where others won't. You live in a world where everything is potentially wrong until proven, and many people will not understand your ideas. Sounds like a recipe for insanity.
The same goes for mystics, isn't it? Questioning reality, "feeling" an otherworldly truth somewhere far beyond, things no one can see, the willingness to consider batshit crazy sounding stuff as real.