Childhood is not dead. Children were worse off when we were hunter-gatherers; they were threatened in medieval times and exploited during the Industrial Revolution. Was it any better in the time of Charles Kingsley or Charles Dickens?

Although religion might be useful in developing a solid moral framework - and enforcing it - we can quite easily develop moral intuitions without relying on religion.

To build and strengthen new connections, the brain needs the challenge of fresh and unusual stimuli. .... There's a lot of evidence to suggest that repetition is bad for brain health, and novelty is good.

While nobody has identified any gene for religion, there are certainly some candidate genes that may influence human personality and confer a tendency to religious feelings. Some of the genes likely to be involved are those which control levels of different chemicals called neurotransmitters in the brain.

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.

Both in Britain and America, huge publicity has been given to stem cells, particularly embryonic stem cells, and the potential they offer. Of course, the study of stem cells is one of the most exciting areas in biology, but I think it is unlikely that embryonic stem cells are likely to be useful in healthcare for a long time.

Over the past 20 years, I have presented many science programmes on BBC1. But none is, I think, more socially important, or of more human interest, than this ongoing series of 'Child of Our Time.'