Can an epidemic be reversed? How?

The idea is that an epidemic can be reversed (or tipped) by making small changes in the immediate environment. Crime for example is viewed as the inevitable result of disorder represented by broken windows, un-repaired buildings, graffiti, aggressive panhandling and trash. The power of context says that small things like cleaning up the environment have a strong effect on behavior. In other words, behavior is a function of social context (p. 150). Teen suicide and teen smoking are provided as examples of how peer groups affect behavior. Teens apparently commit suicide, smoke and engage in other forbidden behavior because someone that they identify with does those things (See Chapter 7). Smoking is not cool, people who smoke are cool (p. 233).