This approach may work for children over the age of 5 or so. But babies and very young children are terrible at planning and aiming for precise goals. When we say that preschoolers can’t pay attention, we really mean that they can’t not pay attention: they have trouble focusing on just one event and shutting out all the rest. This has led us to underestimate babies in the past. But the new research tells us that babies can be rational without being goal-oriented.

Babies are captivated by the most unexpected events. Adults, on the other hand, focus on the outcomes that are the most relevant to their goals. In a well-known experiment, adults saw a video of several people tossing a ball to one another. The experimenter told them to count how many passes particular people made. In the midst of this, a person in a gorilla suit walked slowly through the middle of the video. A surprising number of adults, intent on counting, didn’t even seem to notice the unexpected gorilla.

Adults focus on objects that will be most useful to them. But as the lever study demonstrated, children play with the objects that will teach them the most. In our study, 4-year-olds imagined new possibilities based on just a little data. Adults rely more on what they already know. Babies aren’t trying to learn one particular skill or set of facts; instead, they are drawn to anything new, unexpected or informative.

Part of the explanation for these differing approaches can be found in the brain. The young brain is remarkably plastic and flexible. Brains work because neurons are connected to one another, allowing them to communicate. Baby brains have many more neural connections than adult brains. But they are much less efficient. Over time, we prune away the connections we don’t use, and the remaining ones become faster and more automatic. Moreover, the prefrontal cortex, the part of the brain that controls the directed, planned, focused kind of intelligence, is exceptionally late to mature, and may not take its final shape until our early 20s.

In fact, our mature brain seems to be programmed by our childhood experiences  we plan based on what we’ve learned as children. Very young children imagine and explore a vast array of possibilities. As they grow older and absorb more evidence, certain possibilities become much more likely and more useful. They then make decisions based on this selective information and become increasingly reluctant to give those ideas up and try something new. Computer scientists talk about the difference between exploring and exploiting  a system will learn more if it explores many possibilities, but it will be more effective if it simply acts on the most likely one. Babies explore; adults exploit.

Each kind of intelligence has benefits and drawbacks. Focus and planning get you to your goal more quickly but may also lock in what you already know, closing you off to alternative possibilities. We need both blue-sky speculation and hard-nosed planning. Babies and young children are designed to explore, and they should be encouraged to do so.