I don't know about income in every case, but I do know if you pay for a better school and your kid does a bunch of AP courses, it has a massive impact on their SAT. My older daughter was defo that category and it paid off. My younger daughter didn't apply herself and had lower scores. It's very much about personal discipline as it is having the right education provided for too. And, I know another family who's older daughter went to public school and she's now going for med school while her sister is not. So, again, it's about the person as much as income, but income does open initial doors for opportunity.