There are many things that can cause teens to rebel. During the teen years the area called the prefrontal cortex is developing. This part of the brain allows you to form your own ideas and question others. Teens then start to see they flaws in their parents but hey we all have flaws we are only human. Love is another issue if a parent doesn't show concern for the issues their child is facing and states that they were once a teen and everyone has issues [pretty much to get over it] that child feels lost and unloved. It has even been proven that this generation of teens are under more pressure than ever in history. Of course there was peer pressure back then but at the age of 15-18 now teens are starting to experience it at 13-18. Many teens also don't have a full family. Only 18 out of 100 teens will have both parents in a stable relationship by the time they are 18. Sad right? You just have to understand that they are going through extremely hard times for the first time in their lives and on top of that are trying to find who they are as individuals. If you have a teen talk to him or her about what is on their mind you'll be surprised about all they things they are constantly worried about. If they don't want to talk about it give them their space they will come around soon just assure them that you are there for them and they can tell you anything. DON'T GET MAD AT THEM FOR THEM COMING TO YOU FOR THEIR ISSUES! If you do trust me they will never do it again teens HATE getting yelled at.