Personal story: My dad was a college grad, the first in his family of hard working businessmen, my mom was a farm girl who not only finished HS but did very well with grades. Often times we did not have hardly any money growing up because my dad liked to spend it on himself, and he was a 100% commission paid salesman. But, while we might have looked poorish to some three things pointed to us being of a higher class
1) there were lots of books in the home, and they were used
2) getting good grades was an imperative, poor grades meant that all hell broke lose.
3) we were told that we must be out of the house and self supported at 19 unless we were at university, and that financial success in life was as expected as were good grades.