Childhood depression tends to be more common in inner cities, being most frequently related to serious social deprivation, bullying, domestic violence, wartime experience and famine. It is, for example, a serious problem among children who are traumatised refugees.

I did not study science at school until I was 13, when I was totally turned on by a seemingly dreary old teacher who suddenly, unannounced, manufactured a huge explosion in the middle of a totally boring monologue. From then on, all of his class wanted to make explosions.

I used to work for the World Health Organisation in poor countries all over the world - Bangladesh, Korea, the Philippines and India. You learn a whole range of things about how other people are living and try to connect with them to gain an understanding of where they're coming from.

Nearly all inventions are not recognised for their positive side either when they're made. So, for example, scientists didn't go out to design a CD machine: they designed a laser. But we got all sorts of things from a laser which we never remotely imagined, and we're still finding things for a laser to do.

Whether you're religious or not, there is a real need for other people's religious positions to be treated with the upmost respect.

Man is a competitive creature, and the seeds of conflict are built deep into our genes. We fought each other on the savannah and only survived against great odds by organising ourselves into groups which would have had a common purpose, giving morale and fortitude.

Of course it is a very simple matter to identify genes which might modify intelligence or memory and start thinking about whether you want to enhance a human, and the next generation is going to have to deal with that issue. Should we be trying to enhance humans rather than trying to educate them and so on?