Alison Gopnik

Imagine if baseball were taught the way science is taught in most inner-city schools. Schoolchildren would get lectures about the history of the World Series. High school students would occasionally reproduce famous plays of the past. Nobody would get in the game themselves until graduate school.

Like most parents, I think, my children have been the source of some of my most intense joys and despairs, my deepest moral dilemmas and greatest moral achievements.

What teenagers want most of all are social rewards, especially the respect of their peers.

What happens when children reach puberty earlier and adulthood later? The answer is: a good deal of teenage weirdness.

The science can tell you that the thousands of pseudo-scientific parenting books out there - not to mention the 'Baby Einstein' DVDs and the flash cards and the brain-boosting toys - won't do a thing to make your baby smarter. That's largely because babies are already as smart as they can be; smarter than we are in some ways.

I'm afraid the parenting advice to come out of developmental psychology is very boring: pay attention to your kids and love them.

Siblings are the guarantors that the private childhood world - so unlike the adult world that scientists are only just beginning to understand it - is a fully shared and objective one.

We have lots of evidence that putting investments in early childhood education, even evidence from very hard-nosed economists, is one of the very best investments that the society can possibly make. And yet we still don't have public support for things like preschools.

One of the most distinctive evolutionary features of human beings is our unusually long, protected childhood.

From an evolutionary perspective children are, literally, designed to learn. Childhood is a special period of protected immaturity. It gives the young breathing time to master the things they will need to know in order to survive as adults.

Even the very youngest children already are perfectly able to discriminate between the imaginary and the real, whether in books or movies or in their own pretend play. Children with the most elaborate and beloved imaginary friends will gently remind overenthusiastic adults that these companions are, after all, just pretend.

Children have a very good idea of how to distinguish between fantasies and realities. It's just they are equally interested in exploring both.