Children are very sensitive to what they're exposed to and what their elders tell them. In this way, Dawkins theorises, the narrow-mindedness of faith is spread like a virus from generation to generation. Very few of these children are coming out of school with a mind that is open to the world and everything in it. They're coming out with a whole other fantasy world inside their head, one most of us don't understand, and that world, in their mind, rules the real one that they share with us. Dawkins is successful in his subtle way of showing that although creationists think evolutionaries are the narrow minded ones, preaching your own 'faith' is a far more damagingly selfish act, probably the result of grandiose delusions.