This contains a strong assumption of nature over nurture. I push back on that. (A point of evidence being salivary cortisol correlations with high-stress childhoods and even prenatal environments.)
Independent-minded cultures produce more independent thinkers. A culture that censors raises children by rewarding convention-seeking behaviour and sharply punishing non-conformance.
(Counterpoint: Did the children of circa 1920s academics become academics at a greater frequency than those of postwar academics? Anecdotally, I think so. A lot of them, as PG hypothesises, became founders. That suggests an innate quality that seeks its environment.)
This might also be content-dependent. When I was young, I oscillated between tattletelling and rampant rulebreaking, with a memorable drive to stand out from my peer group. Notably, an inflection point, to my memory and, surprisingly, to my discovery a few years ago after reading childhood notes, was when my family immigrated to America. To-day, I’m passively conformist with the law, but moderately independent when it comes to personal social, political and broader commercial activities, enjoying standing out even if it means being quirky or disliked. I don’t imagine I’d have been the same in Switzerland or in India.