I think to say that the Hallway Hangers are communitarian means that their identities are dependent upon the ideas and identities of the others in the group. Almost like they can't think for themselves. They've become conformists for each other, maybe not wanting to betray, but definitely not wanting to be the "black sheep" of the group. They pretty much have the same views and ideas of the world, and if one didn't, he'd keep it to himself generally.

Their solidarity actually has a negative effect on their lives. As long as they all believe they're not going anywhere in their lives, they won't. None of them will let himself develop any self-esteem, or believe there's more to his life. It has a negative effect on their life chances, too. They've caged themselves into thinking they're only get a certain type of job, and have a certain kind of life. They're really selling themselves short, individually and as a whole, and they don't even realize it.