Of balls and busts

It's not often that neuroscience/economics research hits the headlines, but a paper in this week's PNAS, concerning hormonal influences on the behaviour of individual stock traders, has sired prominent stories in many of today's organs - see, for instance, the Guardian or BBC.

The research is be John Coates and Joe Herbert of Cambridge uni. Their abstract sums it up nicely:
Little is known about the role of the endocrine system in financial risk taking. Here, we report the findings of a study in which we sampled, under real working conditions, endogenous steroids from a group of male traders in the City of London. We found that a trader's morning testosterone level predicts his day's profitability. We also found that a trader's cortisol rises with both the variance of his trading results and the volatility of the market. Our results suggest that higher testosterone may contribute to economic return, whereas cortisol is increased by risk. Our results point to a further possibility: testosterone and cortisol are known to have cognitive and behavioral effects, so if the acutely elevated steroids we observed were to persist or increase as volatility rises, they may shift risk preferences and even affect a trader's ability to engage in rational choice.

It's not a new concept, of course - I wrote about a related behavioural economics study two years ago (a post that, because of the title, is actually one of my most frequently accessed items by people coming to this blog via search engines - I suspect most of them will be disappointed).

And it doesn't take a genius to spot why this is now a lot more newsworthy - boom and bust economics seems to be on people's minds...