People from wealthy backgrounds are more likely than poorer people to break laws while driving, take lollies from children, and lie for financial gain, a United States study says.
The seven-part study by psychologists at the University of California Berkeley and the University of Toronto analysed people's behaviour through a series of experiments.
For instance, drivers of expensive vehicles were observed to be more likely to break the rules at four-way intersections, and were more likely to cut off pedestrians trying to cross the street than drivers of cheaper cars.
In another test using a game of dice, given the opportunity to win a prize, people who self-reported high socio-economic status were more likely than the rest to lie and say that they had rolled higher numbers than they actually had.
People with higher status were also less likely to tell the truth in a hypothetical job negotiation in which they were the employer trying to hire someone for a job they knew was soon to be eliminated.
And when given a jar of lollies that they were told was for children in a nearby lab - though they could take some if they wanted - the richer people took more lollies than anyone else.
Also, in that particular study, researchers conditioned some of the subjects first to think of themselves as of a higher social rank by asking them to compare themselves to others with less.
The exercise showed that people could be trained to think more highly of themselves, and that they would in turn act with more greed and less ethicality, demonstrating that status drives greed.
'Culturally shared norms'
The study, which appears in the Proceedings of the National Academy of Sciences, theorises that a series of factors "may give rise to a set of culturally shared norms among upper class individuals."
For instance, richer people are more independent from others and are therefore less concerned with what others think of their actions than poorer people, the authors suggested.
According to Dr Piff, people with more money tend to look more positively on greed and rely less on family and friend networks for support in times of need, and this elevated status tends to disconnect them from society.
"It is that very different level of privilege in your everyday life that gives rise to this independence from others, this reduced sensitivity to the impact of your behaviour on others' welfare, and the prioritisation of your self-interest," he said.
Certainly there are exceptions, said the study, pointing to famous upper-class whistleblowers at Worldcom and Enron; and wealthy philanthropists such as Bill Gates and Warren Buffett.
Previous research linking poverty and violent crime also disproves the notion that all poor people are more ethical than the rich, it added.
However, self-interest is "a more fundamental motive among society's elite, and the increased want associated with greater wealth and status can promote wrongdoing," it said.
Although the study focused on US subjects, with each of the seven parts measuring between 100 and 200 participants, Dr Piff said the findings are likely to be relevant to societies outside America, too.
"These patterns are going to be particularly salient in societies where wealth is as unequally distributed as it is here," he said.