True for the most part but explaining the “Bell Curve” using only culture might be difficult.
It might be totally explainable.
I’m betting the “Bell Curve” study, if based strictly on culture, would provide nearly identical results.
An additional, interesting study would be to test non-typical people of a different “race” than the norm for the given culture and see how they faired on the curve.
You wouldn’t find many “whites” who were of the Asian culture to study, but you could find enough “white/black” crossovers to study.