Take male strategies for success in the world. If you've got all the advantages, if you're attractive and clever and all of that, you will generally go for very high quality females.

Just as the design of our bodies can be understood only in terms of natural selection, so the design of our minds can be understood only in terms of memetic selection.

All other species on this planet are gene machines only. They don't imitate at all well; we alone are gene machines and meme machines as well.

Imagine a world full of brains, and far more memes than can possibly find homes. Which memes are more likely to find a safe home and get passed on again?

You start by copying other people's paintings or music or whatever. You get all of those skills before you branch out. Really creative people have a fantastic ability to copy things and then combine them in new ways. And whether we're talking about genes or memes, recombination is the real heart of creativity.

In proportion to our body mass, our brain is three times as large as that of our nearest relatives. This huge organ is dangerous and painful to give birth to, expensive to build and, in a resting human, uses about 20 per cent of the body's energy even though it is just 2 per cent of the body's weight. There must be some reason for all this evolutionary expense.

Certainly almost everything we do and think is colored in some way by memes, but it is important to realize that not everything we experience is a meme. If I walk down the street and see a tree, the basic perception that's going on is not memetic.