There's evidence higher IQ leads to better outcomes all the way up the scale.
The graph below shows scores vs outcomes for students scoring in the top 1% of a maths test. It's not flat as your anecdotal caveat would predict:
http://4.bp.blogspot.com/-4b8ThyfDgzs/U29nQEBAQTI/AAAAAAAAE4...
You're 18 times more likely to get a STEM doctorate scoring at the 99.8th percentile vs 99th.
Or a paper linked earlier in the thread: https://www.jstor.org/stable/41038598?seq=1#page_scan_tab_co...
