My 11 y/o daughter was just sent to the principal's office for carving a middle finger out of an eraser and saying that it represented her teacher. Princial said that she and other kids are competing to make each other laugh and be the "coolest kid". She is a very strong, outgoing obnoxious personality - very different from me. She wants to be the center of attention. What receommended discipline do you have? How to I explain "obnoxious" to an 11 year old.