大象传媒

This week Peter Evans eavesdrops on an experiment involving a room full of university students and a pot of money. In recent years, experiments like this have been overturning fundamental assumptions about altruism, long held by both economists and evolutionary biologists. Under attack is the notion that when we do a good deed and behave generously, we only do so if - in the end - there's something in it for us.

Experimental economists such as Ernst Fehr, Simon Gaechter and Herb Gintis have demonstrated that many of us are willing to behave generously towards complete strangers without gain to ourselves, and are willing to incur personal costs in the cause of forcing others - again unknown to them - to behave fairly. This altruistic behaviour has become known as strong reciprocity.

The economists have teamed up with psychologists and anthropologists such as Joe Henrich of Emory University to explore the roots of this behaviour. Anthropologists are particularly interested because strong reciprocity may explain how Homo Sapiens has become by far the most cooperative species of creature on Earth.