Baader-Meinhof phenomenon, also known as frequency illusion.

The term comes from a 1994 submission to a local newspaper in which the author comments on the “spooky” phenomenon of seeing a word, phrase, or idea again after first exposure to it within 24 hours. The name comes from a German terrorist group whose name had been noticed in one instance of the effect.rT1 This is the result of two cognitive processes interacting: Selection attention shapes what we do/do not notice, and confirmation bias which causes us to be on-alert for things deemed noteworthy.rZ1 Sensitization is an intelligence practice that takes advantage of this phenomenon.


  1. Arnold M. Zwicky, “Why Are We so Illuded?,” September 2006, https://web.stanford.edu/~zwicky/LSA07illude.abst.pdf. (See notes.)

  2. “Sunday Bulletin Board: I Have Dubbed It The Baader-Meinhof Phenomenon,” Twin Cities (blog), October 16, 1994, https://www.twincities.com/1994/10/16/baader-meinhof-phenomenon-sunday-bulletin-board/. (See notes.)