There are a few studies on the same subject. Most notably by Paul Piff

Here is the peer-reviewed paper: "Higher social class predicts increased unethical behavior": http://dx.doi.org/10.1073/pnas.1118373109

New York Magazine did a feature story about the study: http://nymag.com/news/features/money-brain-2012-7/

A PBS piece on the study: http://youtu.be/IuqGrz-Y_Lc

And the documentary: "Park Avenue: money, power and the American dream - Why Poverty?" http://youtu.be/6niWzomA_So - also exams the psychology behind power.