Highest gifted score at my kids school was the son of two uneducated immigrants who live in a converted garage in exchange for work. I think it was the Raven test. He got 99 or 100.
Another son of mine has a classmate, one of the brightest and best cared for of his peers, who has two very “have it together” Ivy parents. Her brother is autistic in a way that is going to severely limit his achievements, though he is a very nice boy. I think cases like these , across a spectrum of course, are really common.
