A very interesting paper by Moses Shayo begins by surveying the literature on identity. "People tend to identify more with high status groups than with low status groups," which seems pretty obvious.
But I'm not so sure. A major counter-example: Almost no one in the United States identifies himself or herself as "upper class" or "rich." I know lots of rich lawyers, but they imagine themselves "middle class" just like everyone else. Here is a little data from the 1998 General Social Survey. Given the question:
If you were asked to use one of four names for your social class, which would you say you belong in: the lower class, the working class, the middle class, or the upper class?
Lower Class 5.4%
Working Class 45.1%
Middle Class 45.9%
Upper Class 3.6%
More surprisingly, if you add an "upper middle class" option, it remains a far less popular response than "middle class."
If the social psychologists have it right, why are people so reluctant to proclaim themselves "upper class"? Surely the top 20% of Americans could convince themselves that they are the creme de la creme. But in practice, people would rather identify with the lower class than the upper!
Part of my explanation is that rich people compare themselves to other rich people. Junior lawyers compare themselves to partners, and partners compare themselves to their clients. "Now he's rich; I'm just a working stiff."
But the deeper explanation, I suspect, is that "the rich" are a popular scapegoat for what's wrong with the world. So you can raise your self-esteem by subjectively exiting from your objective income bracket.
I can imagine that distaste for "the rich" discourages work effort. If you succeed too well, you become one of them. But there is a psychological safety valve. If you earn more money than other people do, you identify with your occupation (e.g. doctor) or job title (e.g. executive vice president). That way you can count your millions without counting yourself a malefactor of great wealth.