I just finished a book called Freaks, Geeks and Cool Kids: American Teenagers, Schools, and the Culture of Consumption by Murray Milner, Jr. Most of it was tedious (thus, I skimmed) but it had some interesting insights. Here is one that theorizes why high schools have such intricate status systems/cliques.
Adolescents have more autonomy [than they did as children], but little economic or political power. They cannot change the curriculum, hire or fire the teachers, decide who will be admitted to their school, or move to another school without the permission of adults. At the time of life when the biological sources of sexuality are probably strongest, in a social environment saturated with sexual imagery and language, they are exhorted to avoid sex. In many situations they are treated as inferior citizens who are looked upon as at best a nuisance. They are denied the right to buy alcohol or see "adult" movies and are subject to the control not only of parents, teachers, and police, but numerous petty clerks in stores, movies, and nightclubs who check their IDs.
In one realm, however, their power is supreme; they control their evaluations of one another. That is, the kind of power they do have is status power: the power to create their own status systems based on their own criteria. Predictably, the creation and distribution of this kind of power is often central to their lives.
This reminds me of one of my favorite quotations: The man who is denied the opportunity of making decisions of importance begins to regard as important the decisions he is allowed to make. This was said by C. Northcote Parkinson, an Englishman who devised Parkinson's Law.