You read a bunch of books and you get a bunch of how-tos, and you take a bunch of classes and you learn a bunch of techniques. You set yourself goals and benchmarks. I think people have imported that into their experience of taking care of children.

The youngest children have a great capacity for empathy and altruism. There's a recent study that shows even 14-month-olds will climb across a bunch of cushions and go across a room to give you a pen if you drop one.

Young children seem to be learning who to share this toy with and figure out how it works, while adolescents seem to be exploring some very deep and profound questions: how should this society work? How should relationships among people work? The exploration is: who am I, what am I doing?

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.

Developmental scientists like me explore the basic science of learning by designing controlled experiments.

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

All of us gardeners know that nothing comes out the way you planned. It's a different garden every year, and it's always sort of different from what you were thinking when you began. What it really means to be a good gardener is to work hard to produce an ecosystem that will have enough diversity, enough possibilities, so it's robust, and it's resilient, and it can change when the seasons change. And that kind of robust, unexpected, variable, messy system - that's what you want to create when you're having children, too.