>https://pubmed.ncbi.nlm.nih.gov/28096410/
Just so you know, intelligence and educational attainment polygenic scores are correlated by about .7, so this is pretty much hard evidence for a decline human genetic intelligence potential. In fact, Iceland doesn't even have a culture which emphasizes going to school, so the decline there is likely LESS than in Europe/the U.S. and the effect size is massive. Technology has ravaged the human brain, face it, we're on the decline, the Flynn effect will only took us so far, the death spiral is already here and you're living it every day.