From The Art and Popular Culture Encyclopedia
In sociology, a peer group is both a social group and a primary group of people who have similar interests (homophily), age, background, or social status. The members of this group are likely to influence the person's beliefs and behaviour. Peer groups contain hierarchies and distinct patterns of behavior. In a high school setting for example, 18 year olds are a peer group with 14 year olds because they share similar and paralleled life experiences in school together. In contrast, teachers do not share students as a peer group because teachers and students fall into two different roles and experiences.