This article makes a really compelling argument about how kids today are missing out on learning social skills because they do not have the same amount of free play that we did growing up. It is a long article, but well worth the read. I wish I could gather up a pack of neighborhood kids right now for a game of "kick-the-can"!
http://www.aeonmagazine.com/being-human/children-today-are-suffering-a-severe-deficit-of-play/