Not always, of course. But this study suggests that socially anxious people are better at picking up on others’ subliminal expressions of fear.
Speaking personally, I like a conceptualization of social anxiety that sees the anxious as highly accurate, much more so than a conceptualization that sees the anxious as reading things into situations that aren’t there. I’m much more amenable to having it explained why my perceptions are both accurate and giving me problems (and then helping me figure out what to do with the accurate input I am receiving), than I am to being told I’m imagining it all (and should therefore simply ignore any environmental input I get that the person who’s telling me this thinks doesn’t exist – but how to tell that without farming out my good judgment?).