On connection

I recently read the book Connected - The surprising power of our social networks by Nicholas Christakis and James Fowler. They have, through many years of research come to scientifically explain some of our vague common knowledge about how human networks function. They go so far as to call these networks human superorganisms because of the way they are intradependent and persistent over time.
I am particularly interested in the topic due to my own research and my own hypotheses about social change. One fact stated by Christakis in the 18-minute speech he gave to TED below is intuitively clear to all of us: "Obesity is not a unicentric epidemic. There is not a patient zero of the obesity epidemic, and there was no spread of obesity out from him. It's a multicentric epidemic. Lots of people are doing things at the same time."
I consider this to be a fundamental fact in all kinds of change at a societal level, meaning people living under basically the same living conditions. Humans are have certain choices how they react to their circumstances and the sum of their choices create social change. In the face of political problems that means they can either conform or protest and thus a protest movement is not going to come from one source alone, but from many sources at once which occasionally might join forces.