In this fascinating paper, David Dubois, Derek Rucker, and Adam Galinsky explore the interplay between socioeconomic status and selfishness (or cheating). In the course of their study, they discovered that people at both ends of the spectrum cheat, but for different ends:
[S]ocial class positively predicted unethical behavior; however, this relationship was only observed when that behavior was self-beneficial. When unethical behavior was performed to benefit others, social class negatively predicted unethical behavior; lower class individuals were more likely than upper class individuals to engage in unethical behavior. Overall, social class predicts people’s tendency to behave selfishly, rather than predicting unethical behavior per se.
The second thing they discovered was that the cause of selfishness came from an individuals’ sense of power:
Evidence for this relationship was provided in three forms. First, income, but not education level, predicted unethical behavior. Second, feelings of power mediated the effect of social class on unethical behavior, but feelings of status did not. Third, two distinct manipulations of power produced the same moderation by self-versus-other beneficiary as was found with social class.