I have serious doubts how well someone is paid has anything to do with their ability to feel empathy. I do think making broad, negative generalizations is a sign of lack of empathy however.
Assume those studies are correct (I don't believe that conclusion, personally). It displays a certain lack of empathy to interact with people using assumptions about their presumed sociological groups. This may be the very definition of lacking empathy- abstracting people into groups might make sense in studies, but when those preconceptions bleed into condemning statements, it's just prejudice.
It's easy to have empathy for people like you or that you agree with, but the real test is having empathy for those who aren't / you don't.
