The difference between a society with an average IQ of 100 and a society with an average IQ of 70 is one of intelligence. That's why, for example, any policy that allows emigrations from IQ 70 societies to to Western countries, which usually average around 100 IQ, is a bad policy for those Western countries.
There is no nation without natalism.
Strong claim, hard no.
In 20th century scientific records that's about the difference between pre WW German country schools and the same regions in the later part of WWII under siege and under supplied.
That large difference has been attributed to nutrition rather than intelligence given the same genes, the same schools, the same society, etc.
> True, intelligence is not simple.
At yet there you are, mere sentences later, over simplying it and ignoring significant confounding factors. Deliberate malfeasance, oblivious blind ignorance, ... ?
All the same, I guess I am out of date (in 2017, they were getting 1% - perhaps in 2030, they will be up to 50%? Or back down to 2%?)
In general, I don't think there's any problem with saying some traits we call intelligence are heritable and that has a genetic component. I'm less sympathetic to the idea that intelligence is a simple scalar or a quantity that should be used to prejudge candidates for given technical or social tasks. I mean, if you're good, does it matter that any given person is as dumb as hell? I certainly would rather a talented dumbass than a useless genius as a coworker.