Post-apocalyptic Chicago and a rigid social structure based on character traits? Sounds like a Marxist field day to us. Here, we've got the usual fighting teens and the usual strife. The catch? Some kids have more than one trait (imagine that). They are Divergent… Uh oh, we smell trouble.
Why does a broken-down society offer a better chance to show social structures? What is easier to see? Why are so many young adult novelists attracted to the future as a setting? What does it let them show that the present doesn't?