This has been covered in the excellent documentary, The Human Animal. See it in 4 parts: http://video.google.com/videosearch?q=The+Human+Animal http://video.go

This has been covered in the excellent documentary, The Human Animal. See it in 4 parts: http://video.google.com/videosearch?q=The+Human+Animal http://video.google.com/videosearch?q=The+Human+Animal