It definitely sounds like your child is dealing with something emotional. This can be so hard to define. Start with simple questions like, "Did this behaviour come out of nowhere?", "Has my family or I through the natural course of busy everyday life not noticed a few signs that my child is needing extra attention?", "Are the child's sleep/eating habits ok?", "Who does my child hang out with when I am not with them?". Of course, media does play a part in todays culture. What do you allow your child to watch or read? I used to have nightmares that prompted bedwetting because I dreamed about what I had watched and then was too scared to get up so I wet my bed. It then became habit. While we tell our kids that what they watch is just make believe they are still getting a message in what they watch. I have tried to instill a sense of compassion and empathy in my kids (I hope it's working!) by sharing things like the civil rights movement, the Holocaust (versions set to age of course), showing them that the actions of people affect everyone. Your child is not too young to start seeing the bigger picture of the world. Maybe give your child the example of a pinch. It would hurt them to be pinched and it hurts someone else the same. With power comes responsibility; responsibility to be accountable for your own action. Maybe you know someone in the police field or could ask your local pd if someone could talk to your child about consequences. For some reason, there are strains in our culture that power is so wonderful; who gets the prize for winning the game, who gets the best grade gets recognition, who wears a superbowl ring, who is not thought of as a loser by winning a fist fight or word contest, who has the best ipod, the lastest game, etc, etc. Success can be addicting and euphoric. As adults we know that life is just not like that. In high school I was a geek, so to speak. Yet now, the prom queen and miss everything is now a coke addict and leads a quite unstable life. Now, I lead a happy and productive life. No we are not in the six figure income class, but my family still likes being around each other, we try to make each member feel like they count. In my mind as a teenager I was going nowhere, yet there was no truth to it. Also, listening is a big deal; not letting a sibbling interrupt is a big deal. What kind of jokes does your child tell? Are they at someone else's expense? What do they talk about or have they quit talking to the family at all? It reveals a lot. I know I am probably going on and on, but little things have a way of adding up to something big. A counselor would probably be a good idea, but you have had this person in your life for 10 years and know more than a counselor does about them. I would probably be asking my child, "What can I do to help you understand how wrong what you are doing is?, "What do you get by doing what you are doing?" The child is getting something for the bullying or they wouldn't be doing it. Even if it is for nothing but satisfaction. Get to know your child again. They do change and they don't stay children. We as parents are there to guide the direction from which our children receive messages in this life. Don't be afraid to filter out anything negative. That is your job.