Why do humans play games? Do other animals play? What value does play create in the propagation of the genes? Should we play more, play at work, should we play when we are old? "The average 4 year old laughs 40 times a day; the average 40 year old laughs 4 times a day." Here are some great videos that describe this phenomena. Why Do We Play Games? by Vsauce "The opposite of play is not work, it is depression." -- Brian Sutton-Smith Stuart Brown: Play is more than Fun. TED.com A pioneer in research on play, Stuart Brown says humor, games, roughhousing, flirtation and fantasy are more than just fun. Plenty of play in childhood makes for happy, smart adults — and keeping it up can make us smarter at any age. (Recorded at Serious Play in May 2008, in Pasadena, California. Duration: 26:42.) The National Institute For Play. Patterns of Play BBC interview of Bear that plays with dogs. IDEO's David Kelly intervie