Do note also that IQ is normally distributed only by design. There is no convinsing evidence that I have seen for any cognitive ability being normally distribut

Do note also that IQ is normally distributed only by design. There is no convinsing evidence that I have seen for any cognitive ability being normally distributed, let alone general intelligence—however they define it. Usually cognitive abilities have a step skew to the right. And even IQ fails the sniff test for normal distributions as you can imagine that the difference between 70 and 100 is far greater then the difference between 100 and 130.