In the clip above, filmed in the lab of University of California, Berkeley, cognitive psychologist Alison Gopnik, a particularly charming 4-year-old girl named Esther is playing a game that Gopnik made up. The game is called Blickets. The goal is to figure out which of the clay figures are blickets, as indicated by which clay figures light up the little box.

It's much harder than you might think. I know, because I was sitting next to the camera that filmed Esther from behind one-way glass that day, and I too was trying to figure out which of the clay figures were blickets. And Esther just left me in the dust.

To find out how and why, read "Playing For All Kinds of Possibilities," my story in today's New York Times about how young children play — and what their play suggests about human evolution, cognition, and exploration. Here's part of the opener:

When it comes to play, humans don’t play around.

Other species play, but none play for as much of their lives as humans do, or as imaginatively, or with as much protection from the family circle. Human children are unique in using play to explore hypothetical situations rather than to rehearse actual challenges they’ll face later. Kittens may pretend to be cats fighting, but they will not pretend to be children; children, by contrast, will readily pretend to be cats or kittens — and then to be Hannah Montana, followed by Spiderman saving the day.

And in doing so, they develop some of humanity’s most consequential faculties. They learn the art, pleasure and power of hypothesis — of imagining new possibilities. And serious students of play believe that this helps make the species great.

More at the Times.