How 1-Year-Olds Figure Out the World

How 1-Year-Olds Figure Out the World

Alison Gopnik finds that the process used by little babies to figure out the world has much in common with scientific experiments.

By Alison Gopnik in the Wall Street Journal

Watch a 1-year-old baby carefully for a while, and count how many experiments you see. When Georgiana, my 17-month-old granddaughter, came to visit last weekend, she spent a good 15 minutes exploring the Easter decorations—highly puzzling, even paradoxical, speckled Styrofoam eggs. Are they like chocolate eggs or hard-boiled eggs? Do they bounce? Will they roll? Can you eat them?

Some of my colleagues and I have argued for 20 years that even the youngest children learn about the world in much the way that scientists do. They make up theories, analyze statistics, try to explain unexpected events and even do experiments. When I write for scholarly journals about this “theory theory,” I talk about it very abstractly, in terms of ideas from philosophy, computer science and evolutionary biology.

But the truth is that, at least for me, personally, watching Georgie is as convincing as any experiment or argument. I turn to her granddad and exclaim “Did you see that? It’s amazing! She’s destined to be an engineer!” with as much pride and astonishment as any nonscientist grandma. (And I find myself adding, “Can you imagine how cool it would be if your job was to figure out what was going on in that little head?” Of course, that is supposed to be my job—but like everyone else in the information economy, it often feels as if my work has devolved into answering email and handling administrative tasks.)

Still, the plural of anecdote is not data, and fond grandma observations aren’t science. And while guessing what babies think is easy and fun, proving it is really hard and takes ingenious experimental techniques.

In a clever new paper in the journal Science, Aimee Stahl and Lisa Feigenson at Johns Hopkins University show systematically that 11-month-old babies, like scientists, pay special attention when their predictions are violated, learn especially well as a result, and even do experiments to figure out just what happened.

They took off from some classic research showing that babies will look at something longer when it strikes them as unexpected. The babies in the new study either saw impossible events, like the apparent passage of a ball through a solid brick wall, or straightforward events, like the same ball simply moving through an empty space. Then they heard the ball make a squeaky noise. The babies were more likely to learn that the ball made the noise when it had behaved unexpectedly than when it had behaved predictably.

In a second experiment, some babies again saw the mysterious dissolving ball or the straightforward solid one. But other babies saw the ball either rolling along a ledge or rolling off the end of the ledge and apparently remaining suspended in thin air. Then the experimenters simply gave the babies the balls to play with.

The babies explored objects more—and in different ways—when they behaved unexpectedly. The babies banged the ball when it had mysteriously vanished through the wall, and they dropped it when it had hovered in thin air. It was as if they were testing to see if the ball really was solid, or really did defy gravity, much like Georgie testing the fake eggs in the Easter basket.

In fact, these experiments suggest that babies may be even better scientists than grown-ups often are. Adults suffer from “confirmation bias”—we pay attention to the events that fit what we already know and ignore things that might shake up our preconceptions. Charles Darwin famously kept a special list of all the facts that were at odds with his theory, because he knew he’d otherwise be tempted to ignore or forget them.

Babies, on the other hand, seem to have a positive hunger for the unexpected. Like the ideal scientists proposed by the philosopher of science Karl Popper, babies are always on the lookout for a fact that falsifies their theories. If you want to learn the mysteries of the universe, that great, distinctively human project, keep your eye on those weird eggs.