There is yet another discussion of intelligence raging across the internet just now, sparked by Sam Harris’ interview of Charles Murray and a Vox article critical of that interview. (h/t to PZ) I have been critical of the uses of IQ testing for quite some time now, dating back to 8th grade or so. There is nothing per se wrong with intelligence testing. Nor is it inherently bad to make use of intelligence testing. As part of a job application where one is being asked to perform particular tasks in a particular environment, it’s entirely conceivable that a particular intelligence test or set of such tests might well predict success in that job. However, for many if not the vast majority of public policy purposes, IQ and other intelligence testing will function badly, misleadingly, or both. This is even more true if we make assumptions about how much of a particular test result is due to intraracial genetic factors (factors shared within one race, but not between people of different races).