[YouTube] MINI LECTURE 15 – Conditional vs. unconditional correlation: twin studies overestimate heredity

The genetics of twin studies have a bias showing more heredity than in reality, owing to a statistical artifact. The twin studies for heredity are based on comparing the correlation between 2 identical twins minus that between 2 fraternal ones (assumed to be sharing half their genes). The use of fraternal twins as control is assumed to extract the “environmental” factors. Problem: Correlation is conditional and psychologists think it is unconditional. We show how the math is entirely different. The core error is that genes and environment are not separable and additive.

One-Page Answer to Pinker’s Notion that Violence Has Dropped Since 1945

Nassim just posted this one-page refutation to Stephen Pinker’s claim that violence has dropped since 1945. On his facebook page he says that “journalist-passing-for-scientist” Pinker cites “political science bloggers innocent of fat tails, who seem clueless about the difference between data and information. How to separate anecdote from evidence, sampling error from truth, journalism from science? Well there is something called a “test statistic.”
This also illustrates how to do rigorous statistics in the absence of a textbook recipe for a fat-tailed process, by means of Monte Carlo analyses. I will be teaching a course called “Extreme Risk Analytics” at NYU-Engineering this fall and will have to produce an 80 page lecture notes booklet, which I will write progressively from interaction with the class. SILENT RISK is too advanced, so I need a more introductory book.”