. “While having money doesn’t necessarily make anybody anything,” Piff says, “the rich are way more likely to prioritize their own self-interests above the interests of other people. It makes them more likely to exhibit characteristics that we would stereotypically associate with, say, assholes.”

I'm beginning to think that rich people, as a group, are much more likely to take a "means justify the ends" point of view:

No matter how much money you actually have, you’re likelier to behave unethically if you check the “agree” box next to the following statement: “In order to be a successful person in this society, it is important to make use of every opportunity.”

The article says that the top 20% of America controls 87% of the wealth.

Furthermore, "40% of Americans inhabit the same social class as their grandparents, making the United States less socially mobile than Japan or France."

Just the idea of holding money can make people more selfish:

Disagreeableness was also correlated to job responsibility and recommendations for the management track. This seeming correlation between money and insensitivity perpetuates itself, says Kathleen Vohs, a professor at the Carlson School of Management at the University of Minnesota. “You’re reminded of money, and you act like a jerk. People don’t like you, and you’re reminded of money more.”