Dougal Waters / Getty Images

While stereotypes suggest that poor people are more likely to lie and steal, new research finds that it’s actually the wealthy who tend to behave unethically. In a series of experiments — involving everything from dangerous driving to lying in job negotiations and cheating to get a prize — researchers found that, across the board, richer people behaved worse. But, rather than class itself, the authors suggest that it’s views about greed that may largely explain the difference.

In the first two experiments, University of California, Berkeley, psychologists positioned observers at San Francisco intersections to watch for drivers who didn’t wait their turn at lights or yield for pedestrians. The researchers noted the make, age and appearance of cars — a marker for the drivers’ socioeconomic status — as well as the drivers’ gender and approximate age.

If you ever thought that the guy driving a late-model Mercedes is more of a jerk than the one behind the wheel of a battered Honda, you’d be right. Even after controlling for factors like traffic density and the driver’s gender and perceived age (younger men tend to drive faster and often rudely), drivers of the newest, most high-status cars were much more likely to cut other drivers off.

“The drivers of the most expensive vehicles were four times more likely to cut off drivers of lower status vehicles,” says Paul Piff, a doctoral student at Berkeley and lead author of the study published in the Proceedings of the National Academy of Sciences.

Drivers in fancy cars were also three times more likely than those in beaters to threaten pedestrians by failing to yield when the walkers had the right of way at a crosswalk. So much for the theory that owners of expensive cars try to protect their vehicles from being sullied by common blood!

MORE: The Rich Are Different: More Money, Less Empathy

In five further experiments, researchers looked at moral behavior in more controlled lab settings. The experiments were designed to determine what made people lapse into bad behavior, and how difficult it would be to change it. The results offer some hope in an otherwise bleak picture.

In one study, participants reported their own socioeconomic status and then read descriptions of people stealing or benefiting from things to which they were not entitled. When asked how likely they would be to engage in similar behavior, the richest of 105 undergraduates were more likely admit that they would do so, compared with those from middle-class or lower-class backgrounds. Of course, this finding could simply reflect the fact that the rich are more likely to get away with such things — and therefore may feel more comfortable admitting it — so the researchers also studied actual behavior.

In the next experiment, researchers asked 129 students to compare themselves with those who were either far richer or far poorer than they were. Previous studies have found that this manipulation influences people’s perceptions of class and their own behavior, with those primed to feel wealthy behaving less generously and becoming less sensitive to the emotions of others, regardless of their actual socioeconomic class.

The participants were then offered candy from a jar that they were told would otherwise be given to children in another lab. Those primed to feel rich took more candy than those who were made to feel disadvantaged. Fortunately, there were no children actually waiting for the sweets.

MORE: Study: The Rich Really Are More Selfish

But why would people who feel socially elevated behave less ethically? The next set of experiments sought to examine this question, finding a connection between wealth and positive perceptions of greed. Among adults who were recruited online for one such experiment, those who were wealthier were more likely to lie in a simulated job interview scenario. The participants — acting as managers — were told that their hypothetical applicants would be willing to take a lower salary in exchange for job security. The applicants wanted a two-year contract position, but the managers knew that the available job would last only six months before being eliminated — and that they could get a bonus for negotiating a lower salary. People of high social class were more likely to lie to the job seekers, researchers found.

The reason for this was not necessarily their class, but the fact they agreed with Wall Street‘s Gordon Gekko that greed is good. When the researchers examined the connection between beliefs about greed and unethical behavior, they found that class was no longer a significant variable. In other words, rich people tended to take advantage of others primarily because they saw selfish and greedy behavior as acceptable, not just because they had more money or higher social status.

To confirm this, another experiment examined whether a person’s attitudes about greed or his class status would predict cheating on a dice game. Researchers recruited 195 adults on Craigslist, queried them about their backgrounds and greedy attitudes, and then had them play a computerized dice game in which higher rolled scores meant a higher chance of winning $50. Unbeknownst to them, the computer always generated the same score: 12. People who believed greed was good were more likely to cheat and report inflated scores of 15 or higher.

Then, in a final study in which the researchers primed participants by having them talk about either the benefits of greed or something neutral (what they did that day), they found that poor participants were just as likely as rich ones — if they were primed to think greed was good — to support bribery or to cheat unsuspecting customers. In the neutral prime, rich participants were more likely to support unethical behavior.

MORE: How Economic Inequality Is (Literally) Making Us Sick

Fortunately, people can also be easily primed to behave more generously. In an earlier study, Piff and his colleagues found that rich people were less likely to help a person who entered the lab in distress — except when they’d just watched a video about child poverty. “We’re not arguing that rich people are bad at all, but that psychological features of wealth have these natural effects,” says Piff. “There are simple things you can adjust, which suggest that rich people are fairly sensitive and just need little reminders.”

He notes that billionaire Warren Buffett made a similar point in a New York Times op-ed last year, calling for higher taxes on the wealthiest. “I know well many of the mega-rich and, by and large, they are very decent people,” Buffett wrote. “Most wouldn’t mind being told to pay more in taxes as well, particularly when so many of their fellow citizens are truly suffering.”

In a comment for WebMD, George Mason University professor of education Martin Ford praised Piff’s study. “It is particularly compelling when the same basic phenomenon is demonstrated using a wide variety of experimental methods,” he said.

The findings got me thinking that if we are concerned about negative media content harming the moral development of children, we might want to place positive depictions of greed near or even above sex and violence on the list of exposures that are unsuitable for youth.

MAGAZINE: Getting to No: The Science of Building Willpower

Maia Szalavitz is a health writer at TIME.com. Find her on Twitter at @maiasz. You can also continue the discussion on TIME Healthland’s Facebook page and on Twitter at @TIMEHealthland.