This is Bioethics Bites with me David Edmonds and me Nigel Warburton.

Bioethics Bites is made an association with Oxford's Uyhereo Center for Practical Ethics

and made possible by a grant from the Welcome Trust.

For more information about bioethics bites, go to

W.W. dot practical ethics.

OX.

A train is hurtling towards five people, it's out of control. You're on a footbridge

standing next to a very obese man. The only way to save the five is to push the man over the footbridge to his certain death.

His bulk would stop the train and save five lives.

So should you do it? Should you give him a shove?

Most people would say no. Utilitarians say yes, you should take one life to save five.

Now it turns out that the answer you give will depend on how much serotonin there is flowing through your brain. This raises an intriguing

possibility. In the future, might we be able to alter people's moral

behavior with concoctions of chemicals? That's been the research topic of Molly Crockett, now based in Zurich, but formerly of Cambridge University.

Molly Crockett, welcome to Bioethics Bites.

Thank you very much.

The topic we're going to focus on is brain chemistry and

moral decision-making. You've done a lot of research on serotonin levels and

how those can affect behavior. Could you just say a little bit about that?

Yeah, so we've done a number of experiments

looking at how boosting or depleting serotonin levels

influence decision-making in terms of reacting to being treated unfairly.

...