When a person gives in to peer pressure he is basically searching for his own identity. If he has a secure identity he will approach this group with a positive attitude and realize the things that are acceptable and also those that are not. He needs to be strong enough to say no to bad ideas without being angry or even embarrassed. People with a secure sense of identity can feel close to others without feeling they are losing their individual identity. At this time he will have an urge to search for his own values.
Values are beliefs and standards that are important to live by.
He will learn that his conscience plays a part in his behavior. As you know the conscience is that part of you that separates right from wrong. When he is a teenager and in this period of adolescence he will want to know your reasons behind the rules you set forth for him to live by. Before this period and time in his life he probably did not question your giving him rules and following them. He will also begin to question different things such as politics and may form thoughts that will lead him to support one particular political party.