I don't think it's as simple as whether you're an introvert or an extrovert.

My son is on the extrovert side. He'd love to have friends to hang out with. But he's so sensitive, he gets his feelings hurt when he's around other people. He mostly stays home.

I'm extremely introverted, but I'm around people all the time. (I have to go out and work.) I'm not afraid of other people - either for my physical or psychic safety.

Maybe extrovert-introvert has less to do with fear than with desire to interact with people? It's just unfortunate that my son has that desire but also a great fear.