Availability Heuristic — Overrating What Comes to Mind Easily

The Availability Heuristic is a mental shortcut in which, when judging how often something happens, you substitute the judgment of 'how easily that case comes to mind.'

A concept organized by Tversky and Kahneman in the 1970s, it makes events that are vivid, recent, emotionally arousing, or frequently in the media feel more common and dangerous than they actually are. The brain uses the proxy of 'ease of recall' instead of accurate statistics.

When crash news fills the headlines day after day, the fear that 'it might crash again' grows regardless of the actual probability. Conversely, when stories of someone striking it rich in stocks circulate nearby, the illusion that 'I could do it too' grows, even though success is rare.

Especially a down market you just went through stays vivid in memory, and it can make you overrate risk for a long time afterward. Because the media covers dramatic crashes and surges more heavily than ordinary rises, watching only the news makes the market look far more precarious or more heated than it really is.

The key is not to mistake 'vividness' for 'frequency.'

The habit of checking actual data instead of feelings is your line of defense. For example, when you feel 'it's dangerous these days,' looking directly at decades of drawdown and recovery data lets you coolly gauge how often that event actually occurred and how it recovered.

Not estimating the overall probability from one intense case (the success or failure of someone you know), and thinking about news exposure and actual frequency of occurrence separately, both help.