Overheard on the Internets
Watch the whole thing on Google Video now. Catch it before they take it down.
http://video.google.com/googleplayer.swf?docid=-1839369108234002661&hl=en&fs=true
"In The Play of Man, Groos extended his insights about animal play to humans. He pointed out that human beings, much more so than any other species, must learn different skills depending on the society in which they develop. Therefore, he argued, natural selection led to a strong drive, in human children, to observe the activities of their elders and incorporate those activities into their play. Children in every culture play at the general categories of activities that are essential to people everywhere, but their specific forms of play, within each category, are shaped by the kinds of activities they see around them. When children are free, they play far more, and in a far greater variety of ways, than do the young of any other species because they have far more to learn."