From 2018 (with some spelling corrections):
"You can observe that IQ is heritable in groups, i.e. calculate a heritability percentage that expresses how much of the differences of IQ in the group you studied are due to genetic differences.
So you could say that in a sample from Sweden of say 1000 people, the heritability of IQ was say 75%.
You can do that for different groups and get similar but not the same numbers.
That tells you that IQ differences have a strong genetic component.
Let's say you know (made up numbers) that group A has an average IQ of 100 and a heritability of 70% and group B has an average IQ of 85 and a heritability of 67%.
There is no way to determine how much of the difference in the phenotypic IQ is due to genetic factors without knowing what causal genetic variants are.
It appears plausible to some people that you could just calculate the that from the group numbers (IQ, heritability) but in fact you can't.
It could be that in group B all of the lower IQ is due to uniformly poor environmental conditions for that group, which is why it wouldn't show up in heritability, because that only measures the differences between individual within that group not across other groups.
Bottom line: once we have reliable genomic estimates of IQ, we can make statements about genetic IQ differences across groups. Until then, we should not claim that we can.
Basing demands for political equality on the assumption that there are no genetic group differences is foolish, because if science finds out that there are substantial differences (a very plausible but not guaranteed result), racists will say: "see you said everyone is equal genetically and should be treated equally, but now we know that there are genetic differences between groups and therefore we should treat them differently."
If you base your ethics on individual rights rather than claims about group equality you will not run into this problem."
