This is a really interesting, simple and clever study design and I look forward to reading it. That said, I think there is strong evidence for selection against

This is a really interesting, simple and clever study design and I look forward to reading it. That said, I think there is strong evidence for selection against intelligence at genetic level. The question is more "does it explain the Flynn effect and its reversal", or "is it large enough to have an important effect?" See our paper: https://ideas.repec.org/p/uea/ueaeco/2021-02.html https://ideas.repec.org/p/uea/ueaeco/2021-02.html