I see the time pressure effect on article quality, could have used some editing (muddled message, abrupt ending, could be situating the points better). It feels more like a dense outline than an article.

What it's saying (I think) is that IQ tests measure learnable skills, and population-level changes over time are measuring learned competence and not innate intelligence, proven by statistics.

I think most people would agree that most skills reflect both innate talent and preparation/training. I can get better at running, but could never beat Kipchoge in a marathon, no matter how much I train.