You would think that with as much social networking and texting as teens do, that they would know everything there is to know about each other. They may know who said what in history class, but what they do not really know, is what risky behavior their peers are doing and not doing. The bravado, wild story sharing, and bragging they do share makes teens believe that "everyone" is doing everything, which is absolutely not true!
This misperception, called pluralistic ignorance, is usually a wild overestimate and happens from middle school through college, and applies to drinking smoking, and hooking up. In the mind of a teenager, everyone is have much more fun than she or he is.
The distortion has a real effect on behavior - because teens are especially worried about how they compare to others, and whether or not they fit in. In addition, when they believe that "everyone else is doing it," they want to make their own decisions and reject their parents control.
The misperception that everyone else is doing everything leads teens to drink more, have sex, and even smoke more, because they gage their own behavior on what they believe everyone else is doing. Social norms marketing tries to help teens understand how many teens are really NOT using or having sex so that they can make a more informed decision.
Given that teens tend to want their behavior to be "normal" social norms marketing is sometimes a tough sell - with teens not believing the messages that come from adults, administrators, and others who really do not "get it."