Using Peer Pressure to our advantage

In a 1994 Harvard study that examined people who had radically changed their lives, for instance, researchers found that some people had remade their habits after a personal tragedy, such as a divorce or a life-threatening illness. Others changed after they saw a friend go through something awful... Just as frequently, however, there was no tragedy that preceded people's transformations. Rather, they changed because they were embedded in social groups that made change easier… When people join groups where change seems possible, the potential for that change to occur becomes more real.

Charles Duhigg, The Power of Habit: Why We Do What We Do in Life and Business