"The rich really are different from the rest of us, scientists have found — they are more apt to commit unethical acts because they are more motivated by greed.
"People driving expensive cars were more
likely than other motorists to cut off drivers and pedestrians at a
four-way-stop intersection in the San Francisco Bay Area, UC Berkeley
researchers observed. Those findings led to a series of experiments that
revealed that people of higher socioeconomic status were also more
likely to cheat to win a prize, take candy from children and say they
would pocket extra change handed to them in error rather than give it
back.
"Because rich people have more financial resources, they're less dependent on social bonds for survival, the Berkeley researchers reported Monday in Proceedings of the National Academy of Sciences. As a result, their self-interest reigns and they have fewer qualms about breaking the rules.
"'If you occupy a more insular world, you're less likely to be sensitive to the needs of others,' said study lead author Paul Piff, who is studying for a doctorate in psychology."
http://articles.latimes.com/2012/feb/27/science/la-sci-0228-greed-20120228
The researchers found in experiments that people who are led to feel richer start acting this way, as do winners of lotteries. So it's not entirely innate.
But this does mean that the Republicans' worship of the rich is misplaced; Republicans who are not themselves wealthy tend to be very nice people. I know a lot of such folk, and my experience of them confirms this. But they fail to understand that the affluent captains of industry and politics may talk like them but they don't think like them.
Conversely, poorer people--often disdained by Republicans--tend to have each others' backs (unless they win the lottery...).