He is salt-of-the-earth. She is a snob. Very wealthy couple. What causes/creates snobs? It isn't money. What is it?

Can the poor also be snobs? I think snobs are very weird people. They think they're better than others because of whatever. Poor souls. EVERYONE IS BETTER THAN OTHERS at something. That doesn't mean you should feel superior because of it and look down on those who don't share those attributes. But some people do. Why?