One day not long ago, Augie, a 4-year-old Gopnik grandchild, heard his grandfather wistfully say, “I wish I could be a kid again.” After a thoughtful pause, Augie came up with a suggestion: Grandpa should try not eating any vegetables. The logic was ingenious: Eating vegetables turns children into big strong adults, so not eating vegetables should reverse the process.
No grown-up would ever come up with that idea. But anyone with a 4-year-old can tell similar stories. Young children’s creativity seems to outstrip that of even the most imaginative adults.
How does the ability to come up with unusual ideas change as we grow older? Does it begin to flag in adolescence? Before then? To investigate these questions, we and our colleagues recently conducted several experiments, which we relate in a new paper in the Proceedings of the National Academy of Sciences.
We began with a group of participants of various ages: 4- and 5-year-old preschoolers; 6- to 11-year-olds; 12- to 14-year-old teenagers; and adults. We presented them with a scenario involving a physical machine that lit up when you put some combinations of blocks on it, but not others. Either of two hypotheses could explain how the machine worked. It could work in a usual and obvious way: Some individual blocks would make it light up, and the other blocks were irrelevant. Or it could work in a more unusual way: It would take a combination of different blocks to make the machine light up.
We presented the participants with another scenario as well, also with two possible explanations. This scenario was social: We told a story about Sally, who approached a skateboard, and Josie, who avoided a scooter. How come? The usual explanation was that something about Sally’s and Josie’s individual traits made them act as they did — maybe Sally was braver than Josie. A more unusual, though equally valid, explanation was that something about the situation was important — maybe the skateboard was safer than the scooter.
Presented with these two scenarios, most adults did indeed explain the events by talking about a single block, or about Sally’s traits — they gave the obvious explanation.
Then we added a twist. Another group of participants saw the same scenarios, but this time they saw an additional set of facts that made the unusual explanation more likely than the more obvious one. Would the participants go with the obvious explanation, or try something new?
When it came to explaining the physical machine, the pattern was straightforward. The preschoolers were most likely to come up with the creative, unusual explanation. The school-age children were somewhat less creative. And there was a dramatic drop at adolescence. Both the teenagers and the adults were the most likely to stick with the obvious explanation even when it didn’t fit the data.
But there was a different pattern when it came to the social problems. Once again the preschoolers were more likely to give the creative explanation than were the 6-year-olds or adults. Now, however, the teenagers were the most creative group of all. They were more likely to choose the unusual explanation than were either the 6-year-olds or the adults.
Why does creativity generally tend to decline as we age? One reason may be that as we grow older, we know more. That’s mostly an advantage, of course. But it also may lead us to ignore evidence that contradicts what we already think. We become too set in our ways to change.
Relatedly, the explanation may have to do with a tension between two kinds of thinking: what computer scientists call exploration and exploitation. When we face a new problem, we adults usually exploit the knowledge about the world we have acquired so far. We try to quickly find a pretty good solution that is close to the solutions we already have. On the other hand, exploration — trying something new — may lead us to a more unusual idea, a less obvious solution, a new piece of knowledge. But it may also mean that we waste time considering crazy possibilities that will never work, something both preschoolers and teenagers have been known to do.
This idea suggests a solution to the evolutionary paradox that is human childhood and adolescence. We humans have an exceptionally long childhood and prolonged adolescence. Why make human children so helpless for so long, and make human adults invest so much time and effort into caring for them?
The answer: Childhood and adolescence may, at least in part, be designed to resolve the tension between exploration and exploitation. Those periods of our life give us time to explore before we have to face the stern and earnest realities of grown-up life. Teenagers may no longer care all that much about how the physical world works. But they care a lot about exploring all the ways that the social world can be organized. And that may help each new generation change the world.
