Why do bankers who get huge bonuses sometimes behave badly?
Because they can't help it, says the neuroscientist Paul Zak. Or at least they can help it, but the chemicals released in their brains make it more difficult for them than other people. Zak has studied the effects of oxytocin and what he calls "the biology of trustworthiness". Increased oxytocin in the body increases empathy. "And it's empathy which makes us moral."
Giving money away, hugging, praying can all increase oxytocin. But testosterone inhibits it. And higher levels of social status are associated with higher levels of testosterone. Hence the problem of the bankers' bonuses. What's more, some people are simply wired differently. "Five per cent of the population don't release oxytocin on stimulus. We have a technical term for them in our lab," says Zak. "We call them 'bastards'."