Emil O W Kirkegaard

You can quibble about that, but I think he is largely correct about holding genetic explanations to a higher standard and suggesting such

explanations are socially dangerous, while ignoring the history of harm caused by environmentalist theories. It's a point that

Linda Gottfedson has also made. http://www.udel.edu/educ/gottfredson/reprints/2009fallacies.html …

I agree it's extremely important to recognize that heritability is a thing and that intelligence testing has very strong reliability and validity properties…this is increasingly recognized among policymakers. That does not extend to claims about group differences.

If I took a set of people from the top half of the IQ distribution and dropped them on an island, there would then be a group with a higher average IQ, entirely due to genetic differences.

Even on its face this is incorrect

No, it is correct. Assume an average of 100 and a standard deviation of 15: then the average of the top half is 112. Assume a narrow-sense heritability of 0,5: then the next generation has an average of 106. No further regression to the mean in later generations.

Or assume that you picked from > 2 std and up ( > 132)): average of the first gen would be ~135. Average of the 2nd and later generations, assuming 0.5 narrow-sense heritability, would be ~118. The smartest population in the world.