Spotted at last: "Homo economicus"?

Are we selfish? Economists like to say that, to a first approximation, we are. In other words, that we tend to seek to maximize our own rewards, in a more or less rational manner. The trouble is that this theory (at least, a straightforward interpretation of it) doesn't describe how people behave in many situations. For example, given a sum of money and asked to decide how to split it between themselves and an anonymous stranger, most people choose to give some of it away. This scenario is called the Dictator Game, and along with a handful of similar tasks, it's a problem for the selfish theory. But what if some people do behave in an economically optimal way? What if the economic man, Homo economicus does exist after all - but as a minority of Homo sapiens? This is what Japanese researchers Toshio Yamagishi and colleagues say in a ...