Separated by a Common Language has written an intriguing post about the ways that Americans and the British talk about class– or, to be more accurate, about how Americans talk about occupation (“blue collar”, “white collar”) while the British talk about class.
Phrasing class-talk in terms of job types or income sits well with the American discomfort with class-differentiation. Putting people into classes seems like it’s defining who they are, whereas defining them in terms of job describes what they do and defining them in terms of income is by what they are getting. Doing and getting are activities, and activities are changeable. Being is a state, and more time-stable (a term from linguist Talmy Givón), and therefore perceived as less inherently changeable. If you’re uncomfortable with describing someone as being something, a solution is to describe them as doing something or having something done to them. This fits with the American notion of equality of opportunity.
And thus, the enormous challenges of doing anything about class, when we cannot even speak of it.