Human achievement is entirely a networking phenomenon. It is by putting brains together through the division of labor — through trade and specialisation — that human society stumbled upon a way to raise the living standards, carrying capacity, technological virtuosity and knowledge base of the species. We can see this in all sorts of phenomena: the correlation between technology and connected population size in Pacific islands; the collapse of technology in people who became isolated, like native Tasmanians; the success of trading city states in Greece, Italy, Holland and south-east Asia; the creative consequences of trade.
-- Matt Ridley