I can’t help myself. Even though I asked for studies I have to offer a few anecdotes.
I went to HS with a kid I suspect was profoundly gifted. He had a rough childhood. Bullying, no acceleration or outside stimulation, and worst of all, an ES teacher who egged on the bullies. He reportedly (didn’t know him then) had a breakdown in second grade. What saved him? A good friend. One good friend. There was a bright but not crazy gifted kid in his class who was having trouble at home (divorce, mom started dating and made bad choices) who became his ally. The friend was a tall, good looking, but very countercultural kind of guy (it was the seventies) who explained gifted kid to the rest of the world until the boy was old enough and sophisticated enough to explain himself. (Gifted kid went to big state U but was named a Rhodes Scholar while there. He always loved art more than science and now is a painter living abroad. I think he is married.)
I suspect my FIL was profoundly gifted. What makes his story interesting is that he fled Poland and thus survived the Holocaust. He escaped from Poland with an uncle at thirteen yo right after the Nazis rolled in and spent the rest of the war in Russia. His formal education, spotty up until then since he was sickly and from a poor family, ended at thirteen. He did enroll in college after the war, but had a family to support so had to go to work. Nonetheless he was the CFO of a big engineering firm that he founded with some other refugees. Amazing to think he learned all that math, accounting, and even some engineering, on his own.
My own father was a solid three deviations above normal. He grew up in a small, southern town where no one knew quite what to do with him academically. Teachers wanted to accelerate him a few grades, his mom refused, arguing his emotional and social development were not so advanced and he would suffer. (And she was right! He was pretty immature and backwards.) Other interesting tidbits about my dad: 1) he was incredibly nearsighted, and no one knew until he was in third grade. He had such intelligence and such highly developed coping skills no one even suspected. 2) his tight knit family was involved in various business enterprises, legal and illegal ( we will leave it at that) so that his childhood was very strange. He got sent to the movies for hours and hours at a time to get him out of the house until it was safe to come home.
I offer the last two stories because they depict gifted people in different environments than the ones we typically think of.