We all know about The Tipping Point: (gladwell dot com / books.)
Most people, though, have missed the key teaching from the broken windows theory. This is a crime prevention idea that says that if a neighborhood is filled with small signs of community disrespect (litter, broken windows, etc.) it's way more likely to have violent crime. If you clean up the little things, the crime rate goes down. Malcolm talked about how well this worked in NYC.
Well, here's the latest: it turns out that it doesn't matter at all what the neighborhood is like. New research just published says that what actually matters is what the people who live there think it's like! The absolute ranking of the neighborhood doesn't matter. The truth of the neighborhood doesn't matter! What matters is the story that people tell themselves. The story is the truth.