A brain region that curbs our natural self interest has been identified. The studies could explain how we control fairness in our society, researchers say... [U]sing a tool called the “ultimatum game”, researchers have identified the part of the brain responsible for punishing unfairness...
"Self interest is one important motive in every human," says Fehr, "but there are also fairness concerns in most people."
"In other words, this is the part of the brain dealing with morality," says Herb Gintis, an economist at the University of Massachusetts in Amherst, US. "[It] is involved in comparing the costs and benefits of the material in terms of its fairness. It represses the basic instincts."
and Tim Hartford - "The Undercover Economist: The great giveaway"
Selfishness is one of those issues where economists seem to see the world differently. It is not that economists are incapable of imagining - or even modelling - altruism. They can, but they usually don’t. And there is a good reason for that: people aren’t selfless... In fact, the closer you look at charitable giving, the less charitable it appears to be. A recent experiment by John List, an economist at the University of Chicago, and a team of colleagues, showed that donations are less than charitable after all. Using controlled trials to compare different methods of door-to-door fundraising, Professor List’s team discovered that it was much more effective to raise funds by selling lottery tickets than by asking for money. This hardly suggests a world populated by altruists seeking to do the maximum good with their charitable cash... Robert Frank, from Cornell, wryly observes that those organising fundraising drives for the vast US charity United Way tend to be disproportionately estate agents, insurance brokers, car dealers and other people with something to sell.