Immaturity

The one thing I hate more than cliques is immaturity. I mean, my sister is twelve years old and she acts like she's five. It really bugs me. I don't get how people can stand to be so immature. What do they get out of it? I really hate the fact that some parents encourage this behaviour. My generation is the most immature of them all, I'm willing to bet. In our eighth grade, we have problems in the boys bathroom. Boys do things that three year olds would do. It is very annoying. Why can't anyone see what it's doing to us? Every generation is getting more and more immature, and if someone doesn't stop it, we'll all have the intelligence of five year olds.
If people REALLY want to have an intelligent generation of teenagers, they need to stop encouraging immature behaviour.