At a camp in the wild and windswept Canadian north, a polar bear lopes toward an Eskimo sled dog. In a minute, it will all be over. But wait! The dog is wagging his tail and bowing, all set to play—and to the astonishment of the musher, now the two animals are romping and rolling exuberantly, until the bear finally has to lie on his back for a time-out. To Stuart Brown, MD, a psychiatrist who has spent decades researching play, the whole interaction makes rip-roaring sense. After all, he writes, playing is both a survival skill that helps you cope with life and one of the great creature comforts; it's even a biological necessity, shaping and sharpening our brains. His thoughtful investigation, Play, written with Christopher Vaughan, makes having fun sound like—well, fun, whether you're dancing, flirting, risk-taking, joking, shopping, painting, or working at something you love. Read this book, then start paying back your "play deficit"—and let the good times roll.