There are lots of reasons why people bully.
Bullying is a behavior, it is something people learn. Bullies may also be bullied themselves, or they were bullied at one time or another in their lifetime. People bully because it makes them feel superior to others. They might get power and strength from bullying others. People bully to get attention. They think that it makes them popular, or that bullying may be a way to fit in. Bullying doesn't make someone popular or cool, it just makes them mean. People who bully are often scared about something about themselves, so they try to scare others to hide their feelings or pick on others so they won't get picked on first. Some people who bully are unhappy and they take out their unhappiness on others. Some people who bully feel little or no responsibility for their actions, and often feel the need to control others and may always feel the need to win. Some people who bully may be jealous of the people they are bullying. Some people who bully are unable to understand and appreciate the feelings of others. Most bullies always choose the one person they know they can win against (basically bullies are chickens). People who bully are excellent observers of human behavior.
People who bully use 'differences' to make victims feel badly about themselves, such as "You're ugly, stupid" etc. as an excuse for their bad behavior. It's not the “difference” in the victim that's the problem - it's the bullies who have the problem because they are afraid, jealous, envious, cruel, angry, insecure, and unhappy.
Remember, it's our "differences" that makes us special and unique. You should be proud of who you are. Don't let people who bully take that away from you. Don't give people who bully that power over you.
Even though people who bully cause a great deal of pain for others, they need help too. If they do not learn how to change their behaviors, they usually end up in trouble with the law. By age 24, 60 percent of people who were childhood bullies have at least one criminal conviction. People who continue to bully have many other problems as adults such as more alcoholism, antisocial personality disorders and need for mental health services.
Some people who bully may not even understand how wrong their behavior is and how it makes the person being bullied feel.
The best defense against a people who bully is to LIKE YOURSELF, be CONFIDENT in YOURSELF, and DONT LOOK LIKE A VICTIM. You should never try to beat people who bully at their own game. You can't bully someone who bullies into not being a bully. If you need help, tell an adult you know and trust. It is hard to solve such problems on your own.