Play: How it Shapes the Brain, Opens the Imagination, and Invigorates the SoulAs we become adults, taking time to play feels like a guilty pleasurea distraction from 'real' work and life. But play is anything but trivial. It is a biological drive as integral to our health as sleep or nutrition. In fact, our ability to play throughout life is the single most important factor in determining our success and happiness. Stuart Brown has spent his career studying animal behaviour and conducting more than 6,000 'play histories' of