Play, which I would define as anything we do simply for the joy of doing rather than as a means to an end—whether it’s flying a kite or listening to music or throwing around a baseball—might seem like a nonessential activity. Often it is treated that way. But in fact play is essential in many ways. Stuart Brown, the founder of the National Institute for Play, has studied what are called the play histories of some six thousand individuals and has concluded that play has the power to significantly improve everything from personal health to relationships to education to organizations’ ability to innovate. “Play,” he says, “leads to brain plasticity, adaptability, and creativity.”