I have this...friend. He is currently a hobbyist programmer so up until now he's only worked alone. He's worried that his (very) shy personality will affect his ability to work on a team and have his work constantly scrutinized by others. He's smart, a good programmer, and he loves programming. He also communicates well outside of face-to-face situations (Internet).
So to avoid asking everyone to be psychiatrists, suppose you were interviewing the person described above. They're a good programmer, but they're shy. Would you hire him?