OK, fiction writers aren't (often) scientists so while such discussions might be interesting you should not take them as authoritative & evidence based. It's a slightly eugenic fallacy which assumes that a) poor people are poor because they're stupid and feckless, and no other reason like the inbuilt injustices on our society (it's considerably easier to stay rich than to get rich) and b) education, upbringing and innate intelligence are the same thing. Life situation isn't genetics.