Yeah, I'm a little torn on this. The OP's claim makes sense on its face, but then I think about my own household, where we're solidly upper-middle class, and my

Yeah, I'm a little torn on this. The OP's claim makes sense on its face, but then I think about my own household, where we're solidly upper-middle class, and my wife and I refuse to keep sugary cereals (and most other junks like Doritos or candy, etc) in our cupboard. My daughter has definitely experienced them at birthday parties and at her grandparents'. Would she have "willpower"? I'm leaning towards "yes" because her experience has been that she can rely on people. Perhaps a poor child is simply more likely to have unreliable caretakers, so there's less trust.