As a consequence of your ancestors and mine having spent their lives living in small groups the Social Media world has great interest in Dunbar's Number.

Its been a concern long before the Internet however.

Authoritarianism's rise, which developed along with the move to organized agriculture from a hunter/gatherer existence thousands of years ago and persists in many places today, was due to:

Roots of the Social Network

We developed and in essential nature remain a social, small-group oriented species.* The majority of your ancestors and mine spent their lives relating to no more than a few hundred people. That's how it was from the time we were still in trees to the birth of agriculture. And for many it remains much that way today.                                       *see Dunbar's Number for more on natural human community size

Both Self-Interest and Altruism are inherent motivations in humans and have established roles in evolutionary theory well supported by observation and controlled experiment.

And examples of altruism extend across the biosphere: honeybees sacrificing themselves for the colony, vervet monkeys sounding loud alarms to warn of threats though it draws a predator's attention to themselves, bats regurgitating blood meals for hungry companions... and soldiers storming Omaha Beach in Normandy.

(For a good discussion see Biological Altruism Stanford Encyclopoedia of Philosophy, revised Oct. '08)

Civilizations Are Complex Chaotic Systems*

Some characteristics of complex chaotic systems**:

Many have realized that Twitter, Facebook or any other widely used system of Status Updates could be useful for tracking possible infections and other trends, as well as having application in many other forms of group action and communication.

Sure enough, within an hour of posting, a friend over at the Brennan Center sent this link: http://www.google.org/flutrends/