There is a thought-provoking article in today's issue of The Wall Street Journal (subscriber content at this writing). Matt Ridley discusses the work of evolutionary biologist David Sloan Wilson. Wilson has done some work on cooperative behavior and, according to Ridley, sees cooperation evolving from generosity or altruism. Ridley notes that others in the field see ideas like reciprocity and see groups of people agreeing to punish non-social behavior.
Ridley notes Adam Smith pointed out that this works among small groups of friends and family. But for larger groups of strangers, another mechanism is needed. Smith's idea of division of labor and the corresponding idea of specialization promotes cooperation because of interdependence. We need each other and we benefit from cooperating with each other. As Ridley states "trade dissolves hostility between groups."
This article caught my attention because it connects with insights from Adam Smith: An Enlightened Life by Nicholas Phillipson. In that book, the author recounts that Smith felt the origin of language resides in our need to convince one another of mutual benefit from cooperative behavior.
If you can find an un-gated version of the Ridley article, I strongly recommend it. If you can't, see if you can access it through a library or other legitimate source. Barring that, I again recommend Phillipson's book.