Dr. Rauch: ŇThereŐs really some exciting research going on about brain development that is important parents know about. One of the things that we know is that the brain isnŐt fully done growing and developing until adolescents are 21. And in fact the part of the brain that still needs to develop is the one thatŐs responsible for common sense and good judgment.  So that children particularly need to rely on their parents to help them think through the consequences of their actions at this age.Ó