Why the Claim That Rich People Have Higher Moral Standards Sounds Odd
My guess is that the people of lower-class origin that upper-class people are acquainted with are those climbing out of the lower classes. (Their opposite numbers—those falling out of the upper classes—can be found at any Occupy Wall Street rally.) The upwardly-mobile are likely to be even more “uptight” than those already at the top.
If I recall correctly, C. N. Parkinson wrote an essay on this topic (“La Ronde” in The Law of Delay). I'll try looking for it.