Just found this very rare and valuable data point. https://www.newsweek.com/identical-twins-raised-apart-different-countries-huge-iq-difference-1704836 https:/

Just found this very rare and valuable data point. https://www.newsweek.com/identical-twins-raised-apart-different-countries-huge-iq-difference-1704836 https://www.newsweek.com/identical-twins-raised-apart-differ... There was a 16 point IQ difference between twins. Nurture had a strong impact on IQ in this case.