Neuroeconomics and trust

Today’s Financial Times runs a feature article on neuroeconomics, an offshoot of experimental economics.

Why do people cooperate in experimental games?

…during the games, Prof Smith’s team scanned players’ brains using functional magnetic resonance imaging. The FMRI scan showed that players who co-operated were using parts of their brain called Brodman’s areas 8 and 10. These areas had previously been associated with thinking about the mental activities and the motivations of others, and of delaying gratification to receive higher rewards later. Non-cooperative players did not use these parts of the brain, and neither did those who knew they were playing against computers instead of human opponents.

This, argues Prof Smith, is consistent with the reciprocity explanation: players are thinking about the likely responses of other players and deciding to trust them.

Brain scans are not the only tool of neuro-economists. Other approaches include measuring pulse rates, skin conductivity and hormone levels. And as a result of such experiments, neuroeconomics boasts an eclectic collection of findings – one of them being that ovulating women are less trustworthy than the rest of us…

Would you like to hear more about ovulating women?

Prof [Paul] Zak has also found that women who take part in the trust game while they are ovulating send back substantially less money to their fellow player than other women or than men – crudely, they are less trustworthy. He explains: “The physiological reason is that progesterone suppresses the effect of oxytocin. The evolutionary biological reason is that is that if you’re about to get pregnant, you should be very careful about overreacting to the social signals you receive. In addition, you don’t want to be giving away resources.” Prof Zak points out that since trust is fundamental to economic development, a better understanding of the oxytocin and the physiology of trust could be fundamental for promoting development. The Bangkok Post has already picked up on his work: the newspaper says that since the oxytocin stimulants massage, food and sex are much beloved of Thais, Thailand’s economic development is assured.

For those interested, GMU researcher Kevin McCabe has started a fledgling neuroeconomics blog.