I have known people with many academic degrees and high paying jobs and people who are constitutionally incapable of holding a job because of their lack of mental intellegence.
Some of the degreed people did not have an iota of common sense and I wondered how they got so far in life! Then I realized that they had enough money to pay for everything they needed even if that paying meant that they had to hire someone to reset their GFI switch. (the electrical button on some outlets like in the kitchen or bathroom)
Then the incapable people I've known always had enough to eat and their basic needs met from the meager wages they got from menial jobs or assistance. They (for the most part) were the most happy people!
Intelligence is the ablility to survive to the extent that you are happy with what you got! (to the vernacular prude........"have")
HappyDad