But most “races” average out to about 100, plus or minus a few.
Not according to Herrnstein and Murray. https://en.wikipedia.org/wiki/The_Bell_Curve
And many groups have experienced steady increases in IQ over many years, suggesting there’s more to it than just genetics.
What it suggests to me is that the people who have been saying since the 1970s that IQ tests are racially biased have made progress in biasing them toward blacks.
You may be missing my point here, and getting some ideas backwards.
I had to read a long ways before getting to Murray's bottom-line: IQ is about 60% genetics, 40% environment and blacks average 15 points lower on IQ scores.
So, looking at those same numbers, I think we can say:
Bottom line: the 40% of IQ which is not genetically predetermined is certainly enough, given good education, to raise up an "average" child to well above average or, correspondingly, reduce a potential genius to failure under the wrong circumstances.
Do you disagree?