Class isn't just about income. It's also a cultural thing, reflected in your grammar, clothes, mannerisms, etc. A plumber whose vocabulary includes "ain't" an

Class isn't just about income. It's also a cultural thing, reflected in your grammar, clothes, mannerisms, etc. A plumber whose vocabulary includes "ain't" and makes $40,000 is not of the same social class as an assistant professor with the same salary.