Where it sits
The base rate is the same as it was last week. The detector is new.
Tell it apart
| Aspect | Frequency illusion | Recency illusion |
|---|---|---|
| You think | It's everywhere | It's new |
| Actually | You started noticing | You started noticing |
| Common in | Cars, words, names | Language peeves |
| Named by | Zwicky | Zwicky |
Zwicky coined both, and they're easy to confuse. Frequency illusion is thinking a thing is suddenly everywhere. Recency illusion is thinking a thing is brand new — assuming a usage you only just noticed must have been invented last year, when it may be centuries old.
What it doesn't mean
Nothing at all, beyond the accident of naming. A newspaper reader happened to hear the group's name twice within a short span in 1994 and used it as a label. The name records the example he happened to hit on, not anything about the group itself.
The popular name came from a newspaper column and the academic name from a linguist's blog. It's best understood as a well-described everyday illusion built from two ordinary processes — selective attention and confirmation bias — rather than a single measured effect.
What it really means
The name is an accident, and the accident is worth knowing. In October 1994, Terry Mullen wrote in to the reader-discussion column of the St. Paul Pioneer Press: he had heard the name of the German militant group Baader-Meinhof twice in a short span, and suggested the coincidence needed a label. The label stuck. The militant group has nothing to do with the phenomenon. The name records the example he happened to hit on, not anything about the group.
The better name arrived in 2005 from the linguist Arnold Zwicky, who called it the frequency illusion — accurate, unglamorous, and now in the Oxford English Dictionary.
What produces it is two ordinary processes stacking. The first is selective attention: before you learned the word, or bought the car, your brain filtered those instances out as irrelevant, and now it flags each one. The second is confirmation bias: every flagged instance gets counted as evidence of a pattern, and every hour that passes without one gets counted as nothing at all.
Which is why the feeling is so specifically eerie rather than merely interesting. You aren't experiencing a change in the world's frequency. You're experiencing the arrival of a detector you didn't have on Sunday — and a tally that only ever moves in one direction.
Where it comes from
a surname pair, borrowed by accident
An eponym of accident rather than a derivation. The phenomenon carries the group's surnames only because Terry Mullen, writing to the St. Paul Pioneer Press in 1994, used his own repeated encounters with that name as the example. Any name he had noticed twice would have served.
- 1994
A contributor to a reader-discussion column in the St. Paul Pioneer Press describes hearing the name Baader-Meinhof twice in quick succession and proposes it as a label. The term spreads online after a writer popularises it in 2006.
- 2005
Linguist Arnold Zwicky coins the academic name — 'frequency illusion' — describing it as a quirk of perception in which a phenomenon you've newly become alert to suddenly seems ubiquitous. It has since entered the Oxford English Dictionary.
In real life
- The week after you buy a yellow car, the roads seem to be full of yellow cars. They were always there; you just weren't counting them.
- You look up sonder on Monday, and by Friday you've seen it in a novel, a song title and a friend's caption. The word didn't spread that week; your attention did.
- Someone newly pregnant suddenly notices pregnant people and pushchairs everywhere on the high street.
Questions
Q01I bought a blue Volvo and now I see them everywhere. Did they get more popular?
Almost certainly not. Before the purchase your brain filtered them out as irrelevant; now it flags every one. The base rate of blue Volvos on your commute is unchanged — your filter changed.
Q02Why does it feel uncanny rather than ordinary?
Because two processes stack. Selective attention makes you register hits you'd previously have skipped, and confirmation bias then counts each hit as evidence of a pattern while never counting the misses. The result feels like the world reorganised itself around you.
Q03Is it the same as synchronicity or a sign?
No. Learn the word 'defenestration' on Monday and you'll spot it in a podcast by Thursday — not because the universe is signalling, but because you now have a detector for it that you didn't have on Sunday.
Sources
- 'Frequency illusion' in the OED — Language Log, University of Pennsylvania.
- Ask Language Log: On point — a worked example of the frequency illusion in usage data.