Lesson 4
The Availability Heuristic
See why vivid stories feel common, and count through the base rate when the thing you’re worried about is rare.
Easy to recall isn’t the same as common
A house two doors down is broken into. Within a week the street’s WhatsApp group is pricing doorbell cameras and agreeing that “it’s getting worse round here”. Nobody has looked up how often it actually happens.
That’s the availability heuristic: judging how common something is by how easily examples come to mind. Memory works like a search engine ranked by vividness and recency, not by frequency. A burglary next door, a plane crash on the news, a friend’s dreadful boiler bill: all leap to the top of the results. The news adds its own tilt, because it reports what’s unusual, so what’s in front of you is skewed towards the rare and dramatic.