“IQ measures something specific, linear reasoning so to say, or first order reasoning. So you have a problem, which is well-defined, and you know there is an answer, and you find the answer on the test [see: IQ test]. But in real life, where things are ‘complex’, and there aren’t obvious answers, or maybe no answers, to a particular problem, and things are just multi-dimensional, the IQ stops working, really. It works if you’re just doing pure mathematics, for instance. But if you’re an entrepreneur, then things are much more complicated. So this is the problem with IQ.”

— Jaanus Vogelberg (2018), “The Great Twitter IQ debate: Taleb Won!” (Ѻ), Dec 24

“The world is full of well-educated people who have made stupid choices, a phenomenon referred to by scientists as ‘dysrationalia’. A survey of Canadian Mensa Club members, whose membership is limited to those in the top two percentiles of IQ, demonstrates this nicely. Among those surveyed, 44% believed in astrology, 51% bought into biorhythms and 56% believed that earth has been visited by aliens. Martin Heidegger, a well-respected philosopher, used his keen mind in support of the Nazi party, using spurious arguments to defend reprehensible behavior. William Crookes, who discovered the element thallium, was repeatedly swindled by spiritual mediums but could never be persuaded to give up his spiritualist beliefs. And Isaac Newton, a scientist without equal, lost his fortune in the South Sea Bubble through a fundamental misunderstanding of the nature of markets and human behavior. Smarts, it would seem, are no guarantee of being a rational actor. Yes, the lessons you have just learned will be least available to your mind when they are most needed. Studies suggest that we lose roughly 13% of our cognitive capacity under stress, lending credence to Nassim Taleb's advice: ‘Even once we are aware of our biases, we must recognize that knowledge does not equal behavior. The solution lies in designing and adopting an investment process that is at least partially robust to behavioral decision-making errors.”

— Daniel Crosby (2019), Behavioral Investor [1]