[ipnon]

What I meant is that elite universities like Harvard and Stanford are capturing something like 90% of those 3 sigma high school graduates, not that all Harvard and Stanford students are 3 sigma. That was not the case 100 years ago, and in the 1970s it was a rapidly increasing trend. Thank you for calling out this ambiguity.

[Glyptodon]

It seems pretty hard to believe for that Harvard and Stanford, or even just the more "elite" universities capture 90% of circa 3 sigma high school students. My experience is that desiring to go to Harvard, Stanford, or other "prestigious" schools is way more correlated to the socialization of valuing prestige than anything, and that many of the very smart folks I've met value particular interests or other concerns much more than status signaling. I'm also not sure the most common admissions tools have great usefulness or accuracy into measurement above 2 sigma. (Though I'm sure people are pretty smart at these schools.)