Everyone is a part of different social groups: Your family, your friends, your classmates, your neighbors, your teammates. How you act in those situations is incredibly important.
Every parent (or caregiver) is a mix of these styles over the course of your life, but will usually have one style they use more often. You may also see teachers use similar styles to control their classes.
"Popular" here is not the same as how you might describe the popular kids at school. Many times the popular kids at school actually aren't very nice. Unfortunately, life is just sort of that way.
Bad advice
Bullying is not OK. Recently there has been a large number of teen suicides that have been connected to bullying. This is not about making kids "tougher" or preparing them to deal with the hardships of life. It is hurting them to the point that they would rather be dead than continue living it. It needs to stop, and teachers and parents and society in general has to come together and figure out the best way to do that. Here are some things to keep in mind: