Natalie Haynes: Why have social mobility if this is what it does to people?

The thing is... It turns out that greed, not need, is a great motivator for behaving badly

The thing is that the posher you are, the more likely you are to behave like a bounder, and possibly also a cad. Not my words, you understand. Those of psychologists at the University of California at Berkeley.

Their researchers quizzed people on their wealth, education and social backgrounds to divide them into different classes. Then they gave them a set of tasks which would identify characteristics like honesty and consideration for others.

Sadly for those who had believed that with great power comes great responsibility, it turns out that the higher up the class system you are, the more likely you are to lie, cheat and even break the law. Poshos were cheerily able to lie to a job interviewee about the permanence of a position which might soon become redundant. They were more likely to behave unethically at work if it benefited them personally, and they were also more aggressive drivers.

Doctor Piff, the excellently named psychologist who led the research, concluded that the more well-to-do we are, the more likely we are to display self-focused behaviour patterns, which is California-speak for being a selfish prick. In other words, upwards social mobility may well come with the price of making us, at best, less empathetic and, at worst, unethical.

This is a serious development for those of us who have found ourselves baffled by how much we are suddenly expected to hate poor people, who apparently don't want jobs, pretend to be disabled, and then riot if you look at their attack-dog funny. We're presented on a daily basis with apparent evidence which suggests that, for example, poverty and immorality are intimately linked: people steal because they need to.

But, actually, it turns out that greed, not need, is a greater motivator for behaving badly. Most people don't cut up a pedestrian because they need to get somewhere sooner, otherwise we would mainly get run over by ambulances. Drivers slew over a zebra crossing, with one hand on the wheel and the other pressing a mobile phone to an ear not because they need to get somewhere in a hurry and simultaneously have a phone conversation, but because they want to. And, crucially, they don't see why they shouldn't.

This is known in my house as "they don't mean me" syndrome. As in, sure, driving while texting is illegal, but they don't mean me. I have to send an important message. And while this detachment from society's rules might seem petty, it reveals a deeply destructive mindset. As Dr Piff says: "Greater resources, freedom, and independence from others among the upper class give rise to self-focused social cognitive tendencies, which we predict will facilitate unethical behaviour." So don't feel bad about bashing a banker just yet. Greed is not so good, after all.