At some time or another you’ve probably found yourself in a bar where the richest person present seems to be the slowest to reach for their wallet when it’s time to buy a round. You might wonder whether they were always this mean, and maybe that helped them become rich? Or is there something about having money that’s made them mean?

It’s a complex question and one that can be approached in many different ways. You could take a group of people known to be interested in the topic of money, such as economists, and compare their generosity with others. One study from back in 1993 did just this and found that the number of economics students who admitted to giving nothing to charity was double that of those studying architecture or psychology. The same researchers also found that economics students were less likely to behave kindly in games involving co-operation such as the Prisoner’s Dilemma.

When students were assessed at the start and end of their degree courses, those studying other subjects became slightly more generous as they approached graduation while economics students remained at the same less-generous level throughout. Of course these are averages, so altruistic economics students exist too.

In fact, there is some evidence showing that people who have more money, or who live in more expensive areas at least, might behave more altruistically. Researchers walked around 20 different parts of London, scattering 15 stamped, addressed letters onto the pavements in each area. Then they waited to see how many letters would be found by kindly passers-by and posted. In the richer areas such as Wimbledon 87% of the letters found their way home, compared with just 37% in poorer districts, such as Shadwell.