Seed: You describe children as being “useless on purpose.” What do you mean by that?
AG: It’s related to one of the basic things that came out of our research: Why do children exist at all? It doesn’t make tremendous evolutionary sense to have these creatures that can’t even keep themselves alive and require an enormous investment of time on the part of adults. That period of dependence is longer for us than it is for any other species, and historically that period has become longer and longer.
The evolutionary answer seems to be that there is a tradeoff between the ability to learn and imagine — which is our great evolutionary advantage as a species — and our ability to apply what we’ve learned and put it to use. So one of the ideas in the book is that children are like the R&D department of the human species. They’re the ones who are always learning about the world. But if you’re always learning, imagining, and finding out, you need a kind of freedom that you don’t have if you’re actually making things happen in the world. And when you’re making things happen, it helps if those actions are based on all of the things you have learned and imagined. The way that evolution seems to have solved this problem is by giving us this period of childhood where we don’t have to do anything, where we are completely useless. We’re free to explore the physical world, as well as possible worlds through imaginative play. And when we’re adults, we can use that information to actually change the world.