I suspect introversion is correlated with my IQ because high IQ people enjoy thinking, and thinking is easier when you're by yourself without distractions.
I did volunteer work eons ago for tagfam.org and I test as a middle-of-the-road extrovert but spend a lot of time in geeky circles where most people are basically painfully shy and many people interpret my middle-of-the-road extroversion as "God, what a ridiculous attention monger!!!!!"
I've gotten enough negative feedback over it, I spend less time on forums than I used to. I'm not an introvert but even I eventually give up on bothering if it's mostly downside.
It can be isolating when one has thoughts and ideas that the people around one simply cannot follow or understand.
Of course it’s also often the case that introverts are simply low social status and thus find social interaction generally unrewarding. In that case pretensions of high intelligence are usually just a coping mechanism.
You can also just be labeled as a weirdo and become the target of bullying for sharing your ideas which aren’t well understood by your peers, and therefore you just keep your mouth shut and become an introvert.
