Nassim Taleb has updated his essay against IQ, and I don’t know if Figure 1 there is new or I haven’t been paying attention before, but it is a true eye-opener. It shows how meaningless correlation is in the absence of symmetry, and medicine is full of asymmetries. I shudder to think how much medical literature consists entirely of physicians-cum-naïve statisticians pouring through medical charts gathering data to calculate such correlations. Counting the official and semi-official guidelines based on such flawed papers would be a nice side project.