[mosquito242]

I think it's reasonable to argue that it's less of an either/or and more of a self-defeating cycle.

Lower class life -> desire to escape -> worse habits -> lower class life

and so on.

[zardo]

I think it has more to do with society being class segregated, and the habits that could raise your class (or raise your chances of getting out anyways) are not the social norms in the lower classes.

Then desire to escape step isn't even necessary.

[gozur88]

There's a confirmation bias in that kind of logic, since people who start out poor and work their way into the middle class (or higher) don't "count" any more.