Comment by dan-robertson

For PISA scores, Finland’s have been declining for 25 years and China only produces scores for the top schools in its top-tier cities (and while US averages don’t look so good in comparison, scores for Massachusetts look good, maybe better).

It feels to me unlikely that PISA scores should be particularly related to ‘country average IQ’ (except by confounders like malnutrition rates) where my understanding is that much of the research has been limited or of such poor quality that the topic has become so toxic as to discourage most potential further research.