While it can be hard for teens to resist peer influence sometimes, especially in the heat of the moment, it can also have a positive effect. Just as people can influence others to make negative choices, they can also influence them to make positive ones. A teen might join a volunteer project because all of his or her friends are doing it, or get good grades because the social group he or she belongs to thinks getting good grades is important. In fact, friends often encourage each other to study, try out for sports, or follow new artistic interests.