One break-in

About this video

A house on Omid's street was broken into last month, and everybody talked about it for weeks: the broken window, the police car, the stolen laptop. Now Omid is sure his town has a lot of break-ins, and he is afraid to leave his window open. Yet his uncle, who looks after the town's records, says break-ins are rarer than they were ten years ago. Why does Omid feel so sure of the opposite?

When we ask how often something happens, we rarely count. Instead, without noticing, we ask a quicker question: how easily can I think of an example? If examples come to mind at once, it feels common; if we have to search, it feels rare. The psychologists Amos Tversky and Daniel Kahneman named this in 1973: availability, judging how common something is by how available its examples are in memory.

Often the quick question works, because things we see a lot often are common. But some things come to mind easily for other reasons: they were vivid, recent, talked about, or happened to us or someone we know. None of these makes something common. A plane crash is vivid and reported all over the world, so many people feel flying is very dangerous, yet for each kilometre travelled far more people are hurt on roads, and most car accidents never reach the news. Tversky and Kahneman also asked whether more English words start with K or have K as their third letter. Most said start with K, because words like king and kitchen come to mind at once. In fact more words have K third, like ask, like and make. So when something feels common, ask: is it common, or just easy to remember? Then look for the count, not the story. This video goes with the What Comes to Mind lesson of Knowledge Level 2 on Knaph.

Transcript

1. 0:00A house on Omid's street is broken into. Everyone talks about it for weeks.
2. 0:05Now break-ins feel common. The town's records say they're rarer than before.
3. 0:11We ask a quicker question instead: how easily does an example come to mind?
4. 0:17Vivid, recent, talked-about things come first. Plane crashes make the news; road accidents rarely do.
5. 0:23More words start with K, or have K third? K third, though king comes first.
6. 0:29Is it common, or just easy to remember?