To add my own highly anecdotal evidence: my experience is that most people with a background in computer science or physics have no active model of how consciousness maps to brains, but when prodded they indeed usually come up with some form of functionalism*.
My own position is that I’m highly confused by consciousness in general, but I’m leaning slightly towards substance dualism, I have a background in computer science.
*: Though note that quite a few of these people simultaneously believe that it is fundamentally impossible to do accurate natural language parsing with a turing machine, so their position might not be completely thought through.
And conversely, some of the unusual-ness that can be attributed to IQ is only very indirectly caused by it. For instance, being able to work around some of the more common failure modes of the brain probably makes a significant portion of LessWrong more unusual than the average person and understanding most of the advice on this site requires at least some minimum level of mental processing power and ability to abstract.