It is called the Baader-Meinhof phenomenon or the frequency illusion.
Baader-Meinhof is the phenomenon where one stumbles upon some obscure piece of information—often an unfamiliar word or name—and soon afterwards encounters the same subject again, often repeatedly. Anytime the phrase “That’s so weird, I just heard about that yesterday” would be appropriate, the utterer is hip-deep in Baader-Meinhof.
damninteresting.com / The Baader-Meinhof Phenomenon, by Alan Bellows, March 2006
Stanford linguistics professor Arnold Zwicky coined [the term "frequency illusion"] in 2006 to describe the syndrome in which a concept or thing you just found out about suddenly seems to crop up everywhere.
It’s caused, he wrote, by two psychological processes. The first, selective attention, kicks in when you’re struck by a new word, thing, or idea; after that, you unconsciously keep an eye out for it, and as a result find it surprisingly often. The second process, confirmation bias, reassures you that each sighting is further proof of your impression that the thing has gained overnight omnipresence.
psmag.com / There's a Name for That: The Baader-Meinhof Phenomenon / by Pacific Standard staff
itre.cis.upenn.edu / Just Between Dr. Language and I / by Arnold Zwicky on Language Log
Update, July 2022:
Since then, OED1 has added the definitions for both terms as well:
- Baader-Meinhof phenomenon, from 1994:
attributive. Designating a quirk of perception whereby a phenomenon to which one is newly alert suddenly seems ubiquitous. Chiefly in Baader-Meinhof phenomenon.
Also called the frequency illusion
- frequency illusion, from 2005:
n. a quirk of perception whereby a phenomenonbr>to which one is newly alert suddenly seems ubiquitous.
Also called the Baader-Meinhof phenomenon
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