Comment by ndriscoll

The assumption is that upper class kids are more likely to have the types of behaviors and attitudes that you'd like your kids to adopt (e.g. getting a C or even a B is embarrassing/shameful, AP classes are table stakes, drug use bad, video games/tv limited, more likely to have intact households, expected to be polite/treat others respectfully) while lower class kids are more likely to have the types of behaviors and attitudes you'd like your kids to avoid (e.g. no point in applying yourself, parents have no idea what you're up to or how you're doing in school anyway, drug use normal or cool, kids raised by tv/computer/phone, family tree is more of a chain with random links sticking out, family yells at each other so loud the neighbors hear it). It's an attempt to manipulate the Overton window that your kid will encounter interacting with peers.