There is a big correlation there. Edit: But I guess it might be that people showing low ability at 5 are more likely to be long-term higher-ability kids underperforming their future ability level if their parents were higher.

> then why do you even go through the motions of K-12

To learn things I would guess.

I don't understand your suggestion. Are you saying that if we can predict someone has a high probability of being a C or D student that they shouldn't go to school at all?