Here’s a sobering thought: The older we get, the harder it is for us to learn, to question, to reimagine. This isn’t just habit hardening into dogma. It’s encoded into the way our brains change as we age. And it’s worsened by an intellectual and economic culture that prizes efficiency and dismisses play. Alison Gopnik is a professor of psychology and philosophy at the University of California, Berkeley, where she runs the Cognitive Development and Learning Lab; she’s also the author of over 100 papers and half a dozen books, including “The Gardener and the Carpenter” and “The Philosophical Baby.” What I love about her work is she takes the minds of children seriously. The child’s mind is tuned to learn. They are, she writes, the R. & D. departments of the human race. But a mind tuned to learn works differently from a mind trying to exploit what it already knows. So instead of asking what children can learn from us, perhaps we need to reverse the question: What can we learn from them? In this conversation, Gopnik and I discuss the way children think, the cognitive reasons social change so often starts with the young, and the power of play. We talk about why Gopnik thinks children should be considered an entirely different form of Homo sapiens, the crucial difference between “spotlight” consciousness and “lantern” consciousness, why “going for a walk with a 2-year-old is like going for a walk with William Blake,” what A.I. researchers are borrowing from human children, the effects of different types of meditation on the brain and more.