Concept
Size Instinct
The size instinct is our tendency to judge a number as big or small on sight, without comparing it to anything, dividing it by the population it covers, or asking how common the thing it measures is.
Hans Rosling named this habit in Factfulness. A lone number feels like a fact, but it has no size until it sits next to something. Big figures feel important simply because they are big. The first figure we hear also quietly becomes the yardstick for everything after; that is anchoring at work. News headlines, sales decks and political speeches exploit this constantly. "4,000 complaints" sounds alarming until you learn the company has 9 million customers. Rosling's antidote is plain arithmetic, not cynicism. Compare: what was it last year, somewhere else, or against the alternative? Divide: per person, per customer, per kilometre driven. Then look for the few items that make up most of the total, because the 80/20 pattern hides inside many lists. The goal isn't to dismiss numbers. It's to give them a size before you react.
A real-life example
A local headline reads: "1,200 people hurt in e-scooter accidents this year." Dana, a city council aide, feels it's a crisis. She checks two things. The city logged 38 million scooter trips, which works out to about 3 injuries per 100,000 rides. Car crashes in the same city injured 9,000 people. The scooter problem is real and worth fixing, but it isn't where most of the harm is. Her memo changes from "ban scooters" to "build better bike lanes."
How to use it
- 1Compare before you react: put the number next to last year's figure, a similar place, or the alternative it replaces.
- 2Divide by the base: turn totals into rates per person, per customer or per use, so a big country or a big company doesn't fake a big problem.
- 3Ask how common it is: find the few items that make up most of the total and spend your attention there.