I seem to recall my grandmother telling me this about 50 years ago.
I have encountered quite a few of the nouveau riche, barely upper middle class, that are unscrupulous and almost unbearable. And I have met a number of very wealthy people, both old money people and the accidental rich, who are kindly, enjoyable, and exceptionally hospitable.
From my own experience it is not whether a person has money per se. Rather it is the perceived power that a person feels that they have and their attitude towards it, and how differently they consider themselves to be therefore from others.
I have heard that it is easier for a camel to pass through the eye of a needle than a rich person to get into heaven. Perhaps it is a simplicity of heart that opens such doors for us, and the baggage of pride that closes them. None of the spirit can justly feel such pride compared to another. Our comparison, our aspiration, is not to the fellow next to us, but to a model so perfect and so loving that it leaves us equally alike in our unworthiness, attempting that which is unattainable to us on our own, except for the undeserved gift of grace.
But the world says 'Greed is good, baby.' Build the foundations of society on that historically untenable aphorism and enjoy the ride. It's been done many times before.
"Seven studies using experimental and naturalistic methods reveal that upper-class individuals behave more unethically than lower-class individuals. In studies 1 and 2, upper-class individuals were more likely to break the law while driving, relative to lower-class individuals.
In follow-up laboratory studies, upper-class individuals were more likely to exhibit unethical decision-making tendencies (study 3), take valued goods from others (study 4), lie in a negotiation (study 5), cheat to increase their chances of winning a prize (study 6), and endorse unethical behavior at work (study 7) than were lower-class individuals.
Mediator and moderator data demonstrated that upper-class individuals’ unethical tendencies are accounted for, in part, by their more favorable attitudes toward greed."
Higher Social Class Predicts Unethical Behaviour, Proceedings of the National Academy of Sciences of the United States of America, February 27, 2012 Paul K. Piffa, Daniel M. Stancatoa, Stéphane Côtéb, Rodolfo Mendoza-Dentona, and Dacher Keltnera
"According to Piff, unethical behavior in the study was driven both by greed, which makes people less empathic, and the nature of wealth in a highly stratified society. It insulates people from the consequences of their actions, reduces their need for social connections and fuels feelings of entitlement, all of which become self-reinforcing cultural norms.
“When pursuit of self-interest is allowed to run unchecked, it can lead to socially pernicious outcomes,” said Piff, who noted that the findings are not politically partisan. “The same rules apply to liberals and conservatives. We always control for political persuasion,” he said."
Greed Is Not Good, Wealth Can Make People Unethical