[speekinout]

I have VERY SERIOUS doubts that work ethics alone without at least "bright" IQ level would have sufficed there.

Not all children of bright parents are bright or motivated themselves. It takes both. In the system I remember, kids who weren't able to keep up with the "A" track had to move to the "B". Some of them couldn't keep up because they weren't bright enough, and others because they were lazy.

[GSlob]

"Not all children of bright parents are bright or motivated themselves. "
True. The latest estimates of IQ heritability are in the range of 70-80%. It is less than perfect 100%. Motivation is something the parents could [and should] instill, but no amount of motivation would ever suffice to make up for a serious lack of ability. Motivated ineptitude could carry a person only so far. I could turn myself inside out, and then back again, but I would never become an equal of Michelangelo, or even of a lesser luminary.