This Sunday, the New York Times magazine section had a big article on the theory of social contagion to explain obesity, happiness, smoking, non-smoking, etc. 

Like every theory, causality cannot be fully determined.  For example, there is a direct correlation between when asphalt melts and babies die.  Melting asphalt doesn’t kill babies.  The heat makes asphalt melt and over-exposure to the heat can kill babies.  So, here, too, social contagion theory can show correlation but not causality. 

If the theory has some merit, we can influence, and be influenced by, others. Maybe that is why one person can spark a movement. And why acting responsibly and teaching by example can change the world.

I want desperately to believe in this theory for the good that it represents (and I am a little scared of its power to spread evil).  Then Gandhi, Mandela, Moses, Jesus, the Islamic prophet (whose name is not to be uttered) are not flukes. 

Why did the Berlin Wall come down? Maybe social contagion.  How do people rise up against despots?  Maybe social contagion.

Unfortunately, by the same token, social contagion can explain atrocities across the globe.

As with most things, the trick is to harness the power, dedication and focus for good.  These days, that seems like a daily challenge.