Still, Roughly one third to one half of the billionaires (45.0%), Fortune 500 CEOs (38.6%), Senators (41.0%), and federal judges (40.9%) attended a school requiring standardized test scores that likely places them in the top 1% of ability. https://www.psychologytoday.com/files/attachments/56143/wai-... Further, why that's only a proxy for intelligence, those with different backgrounds may also have unusually high IQ's.
Granted we are now using a proxy for g to estimate IQ. But, as I was saying intelligence not scores on IQ test IMO it's a valid approach.