It is unclear to which extent the truly exceptional ability is a result of just being lucky that the random parts of the development process resulted in right kind of circuitry.
In twin studies this is partitioned out as “non-shared environment.” In the central range it explains less variation than genetics, but more than household-level environment.
In twin studies this is partitioned out as “non-shared environment.” In the central range it explains less variation than genetics, but more than household-level environment.