We've all met one. We all have our stories of girls who made fun of us in middle school or of cliques that excluded us for years. These girls are unkind, insecure girls who prey on other girls to make themselves feel better. They are more commonly known as mean girls. These are the girls who made us cry on the playground. These are the girls who seemed to thrive off the game of social exclusion. The girls who entered middle school and all of a sudden seemed so much meaner. These girls were queen bees in high school. They earned their reputation as mean girls by bullying, lying and excluding. We all have stories about the mean girls we encountered as teenagers. Whether it was a girl who bullied us in middle school or a girl whom we met in college, everyone has personal experiences with mean girls.

Leading psychologists believe there are three different explanations for why girls behave so abhorrently, and it all comes back to the actual girls themselves.

1. Many girls behave in this way because they don't know any better. Some of them grew up in a home with a mother who is still a mean girl. They hear the way she talks about other women and the way she speaks to her friends, and they mimic her behavior. They see their older sisters treating people poorly or gossiping about people, and they go on to imitate that behavior as they get older. These behavior patterns are habitual, and many teenage girls don't know anything different -- it was in their environment from a very early age, and they had no one to teach them any better.
2. Many girls are mean to others because they do not possess the ability to express their feelings in an appropriate manner. They are unable to vocalize or appropriately express their feelings of hurt or anger, and as a result, they lash out when they feel upset. They take these feelings out on other girls by gossiping about friends or playing exclusion games. This is quite common among girls of all ages. Unfortunately, many girls never grow out of this, and they continue this pattern throughout college and into their adult lives.
3. Finally, many psychologists believe that girls behave this way because they are victims of bullying themselves. They, like so many girls before them, are treated poorly, and their self-esteem plummets. As a result, they become mean girls themselves and begin to treat the world as poorly as they have been treated.

Though these girls seem to rule school, they are not what they seem. They project an image of self-confidence and assurance; however, this could not be further from the truth. These girls have been stuck in a vicious cycle of insecurity for their whole lives. They never stopped comparing themselves to other girls and never learned to be happy with themselves. More importantly, they never learned to be confident in themselves. This extends beyond physical self-confidence. Mean girls never learned to love themselves. They became so wrapped up in misery and self-doubt that they began to make themselves feel better by tearing other women down. It's a miserable pattern that goes on and on.

Mean girls exist everywhere, whether you're a 13-year-old in middle school or an adult who is out of college. We should try not to waste our time worrying about these girls, because they are not worth the effort. Instead, we should feel sorry for them, because living a life with no self-confidence, constantly comparing yourself to other women, would be quite miserable.