Al, I’ve always figured the at about 50/50.
First, without proper, readily available, groceries/calories, nothing is going to excel.
Second and equal; You don’t get an NFL lineman out of undersized parents without the proper genes.
Agree. Both are critical!
You also can't get an NFL lineman regardless of genetics if they are severely caloric limited during critical growth periods.
My community took in lots of Vietnamese refugees during the 70s. I did sports with my age peers, and have helped coach their children in the next generation. The children uniformly tower over their parents. All of the boys that I know are taller than their fathers. All of the girls are taller than their mothers. Some of the girls are taller than their fathers. (I always thought that was a very interesting observational study!)
