(Revised draft: added comments on sinister country profiling. Also 1) Used the same data as researchers to find that R² for IQ-wealth and IQ-income is effectively 0 in spite of the circularity. 2) Turns out IQ beats random selection in the best of applications by less than 6%, typically <2%, as the computation of correlations have a flaw and psychologists do not seem to know the informational value of correlation in terms of “how much do I gain information about B knowing A” and propagation of error (intra-test variance for a single individual). 3) Added information showing the story behind the effectiveness of Average National IQ is, statistically, a fraud. The psychologists who engaged me on this piece — with verbose writeups —made the mistake of showing me the best they got: papers with the strongest pro-IQ arguments. They do not seem to grasp what noise/signal really means in practice. )
Why we can???t predict IQ from genes
Some genes are simple. It’s easy to predict eye color. Some genes are complicated. It’s hard to predict how tall your child will be.…