Here is a medical test scenario. A disease affects one in a thousand people. There is a test that is ninety-nine percent accurate. You take the test. It comes back positive. What is the probability that you actually have the disease?

Most people say: ninety-nine percent.

The actual answer is just under nine percent.

If that number seems impossible — if you want to go back and check the problem — that reaction is exactly what this episode is about. Our intuitions about probability are not just slightly off. They are systematically, predictably, and consequentially wrong in ways that affect our medical decisions, our legal judgments, our financial choices, and our assessment of risk in nearly every domain of life.

Shawn and Claire cover what probability actually is, why we get it so reliably wrong, and what a more calibrated ...