Further down in the thread, they seem to confirm the obvious interpretation—it’s not that college graduates are becoming less intelligent, but that a college education is more accessible, and graduates come from a wider pool. Similarly, high school dropout rates have fallen sharply[1] over the last few decades.<p>Whether that’s good or not is beside the point—but the title is misleading (although presumably accurate).<p>1. <a href="https://nces.ed.gov/programs/digest/d07/tables/dt07_105.asp" rel="nofollow">https://nces.ed.gov/programs/digest/d07/tables/dt07_105.asp</a>
I don't know about IQ (whatever that might really be), but I do know that the whole concept of high school has changed since the 50s and 60s. Back then the intent was that the degree should prepare you to be a fully functioning adult and citizen. I read that a majority of big company CEOs in the 50s did not attend college, but can't find a confirming link for this comment. Certainly few people went to university back then, yet society functioned just fine, for the majority at least.<p>Now much of the first year of college in the US seems to be "leveling up" on stuff that should have been in high school, like writing (source: discussions with friends who teach University). Certainly you see this with California high schoolers, where despite its riches the schools are in a parlous state.
A much higher fraction of high school students are going on to college today. High schools may not operate as if they are the end of the student's education anymore. They can pass off students to college assuming college will fix any deficiencies through remedial courses.<p>Who is hurt, of course, are the students that can't or choose not to go to college. Their high-school education deficiencies stick with them.