I've always kind of joked that liberals are the ones who were really good at english, lit, social studies and such in school.
Conservatives were the ones who were good at math.
I'm kidding when I say that, but there's some truth in it. I'm a social worker, and most of my colleagues are liberals. Most of us didn't go into other fields because we can't do advanced math beyond high school algebra or geometry. There are of course some conservative social workers, mostly religious conservatives.