Scientific Thinking

Charlie Munger, the longtime business partner of Warren Buffett and one of the most consistently successful investors and thinkers of the past century, has a theory about intelligence that diverges sharply from conventional understanding. Munger does not believe that raw intellectual horsepower, the ability to process information quickly, hold large amounts of data in working […]

Ask someone whether more people die each year from shark attacks or from falling coconuts. Almost everyone answers shark attacks. The actual answer is coconuts. Falling coconuts kill roughly 150 people per year worldwide, while shark attacks kill fewer than ten. The disparity in perceived risk has nothing to do with the actual statistics and […]

You are three-quarters through a terrible novel. You have already spent eight hours reading it and find it tedious, poorly written, and a waste of your time. Do you keep reading? If you do, you are committing the sunk cost fallacy, allowing past investment that cannot be recovered to distort a decision that should be […]

Most people treat their beliefs like possessions. Once formed, beliefs are defended, protected, and rarely surrendered without a fight. This is not stupidity or stubbornness. It reflects how human cognition evolved. Our ancestors needed stable mental models of the world to act decisively, and constant belief revision would have been paralyzing. But in a complex […]

Every decision made under uncertainty involves the possibility of being wrong in two fundamentally different ways. You can conclude that something is true when it is actually false. Or you can conclude that something is false when it is actually true. These two errors are not mirror images of each other. They have different causes, […]

A disease affects one person in every thousand. A medical test for this disease is 99 percent accurate, meaning it correctly identifies 99 percent of sick people and correctly clears 99 percent of healthy people. You take the test and the result is positive. What is the probability that you actually have the disease? Most […]

Countries that eat more chocolate per capita win more Nobel Prizes per capita. Ice cream sales and drowning rates are strongly positively correlated. The number of Nicolas Cage films released in a year correlates with the number of swimming pool drownings. Shoe size correlates positively with reading ability in children. These examples are amusing precisely […]

The normal distribution is the most important mathematical object in all of statistics, and understanding it is not optional for anyone who wants to reason clearly about the world. It appears with such regularity across nature, science, and human affairs that its discoverers initially believed they had found a law of nature itself rather than […]

In 1944, mathematician John von Neumann and economist Oskar Morgenstern published Theory of Games and Economic Behavior, a work that would eventually transform economics, political science, biology, psychology, and military strategy. Their central insight was deceptively simple: rational decision-making cannot be analyzed in isolation because the outcomes of most real decisions depend not only on […]

Every meaningful decision you make in conditions of uncertainty involves the same fundamental problem: distinguishing a real signal from background noise. The doctor examining an X-ray must decide whether a faint shadow is a tumor or an artifact of the imaging process. The security screener must decide whether the shape in a bag is a […]