Good-looking people enjoy what economists/sociologists call a "beauty premium." They get paid more and are seen as better at their jobs than people of average attractiveness. It works for men and for women. Men, for example, get a premium for being taller, in shape, handsome, and with a nice head of hair.
Now here's where it gets interesting. A new Israeli study suggests that male professors get a beauty bump, but female professors don't. The researchers guess that this is rooted in a "contradiction between... role images and gender images": somehow, female attractiveness is seen as incongruous with the paternal, traditional scholar/educator role of the professor, where male attractiveness isn't -- particularly, it seems, for female students. That's the idea, anyways.
I don't endorse this conclusion, but there's definitely something going on here. A couple of things that came to my mind on reading this: