Seeing the sun rise again tomorrow over the jungle is about as basic as human hope gets, even if the jungle consists of ivy and smelly humidifiers, but characters who spend most of their time inflicting or enduring gratuitous peer cruelties aren't going to have much energy left over for the edification of the self or service to others. If the ancient ethos of the American upper classes "To whom much is given, much is expected" (Luke 12:48) retains any meaning in this setting of muffled barbarities, it's only because what is expected is not public mindedness or moral awareness but worldly success: fame, fortune, social position.
Civilization presumes and promotes survival, while "class" used to be and perhaps still is a way of referring to behavior that meets a society's highest standards. The path upward begins with the recognition that tomorrow is another day and you will live to see it; there will be food, water, and shelter, and if human beings have gathered themselves into groups camps, villages, cities to provide these essentials, they will also have developed codes of behavior to ensure that things don't get out of hand in ever closer quarters. Manners are a social lubricant, and it is no coincidence that the most sophisticated sets of manners have evolved on crowded islands: Japan, Britain, even Manhattan, whose closely pressed denizens don't get enough credit for keeping their elbows in.
Boarding schools are crowded islands too, and (one would think) at least as in need of a social credo as those other places. Classiness matters most in tight situations that tempt our lowest inclinations, and while the classless society might be a fantasy a phantom visible only in the pages of fiction the rituals of grace are as real as we care to make them.*