I am fascinated by the reverse Flynn effect - do you have a favorite theory to explain it?
But for example, in Denmark, when plotting measured IQ against first name, we observe that there is cultural effect, that would explain that the "reverse Flynn effect" is simply an averaging down, caused by the import of migrants from lower IQ regions. The "reverse Flynn effect" is not observed in Singapore, for example, which has maintained consistent high IQ over many years.
https://emilkirkegaard.dk/en/2019/06/article-out-first-names...