Austrian economist Ernst Fehr and his co-authors showed that testosterone, despite its reputation as a promoter of aggressive behaviour, actually made people more cooperative when playing economic games. Fehr's most recent work focuses on so-called neuroeconomics, which explores the roots of our social instincts and emotions. That our precious moral values may ultimately be biologically based upsets some people, Fehr admits, but science is science. "I'm quite happy with whatever I find," he says. "You have to accept what the data tell you."