What is the Baader-Meinhof phenomenon?
The research term is the frequency illusion. What it describes is a change in what a person registers, not a change in how often something occurs.
Answer to the question
What is the Baader-Meinhof phenomenon?
The frequency illusion is the impression that something you have just noticed is suddenly everywhere, though how often it occurs has not changed. Arnold Zwicky coined the term in 2005. Selective attention, a pull towards confirming instances and judging frequency by ease of recall all feed it.
Key takeaways
- Arnold Zwicky coined frequency illusion in a Language Log post dated 7 August 2005 and called it a selective attention effect: once people notice something, they register nearly every instance, and their estimates of its frequency drift upwards.
- Nickerson's 1998 review collects experiments in which people noticed and remembered information that fitted what they already believed.
- Tversky and Kahneman (1973) found that most of 152 participants judged K, L, N, R and V more common as first letters, when all five are more common in third position.
- A record kept independently of your own noticing separates a real rise in frequency from the illusion.
In 1973 Amos Tversky and Daniel Kahneman asked 152 people whether K, L, N, R and V turn up more often as the first letter of an English word or as the third. Most said first, at a median of two to one. All five occur more often in third position. That gap between ease of recall and the true count sits behind the frequency illusion, which popular writing calls the Baader-Meinhof phenomenon.
The experience is a familiar one. After noticing something for the first time, such as an unusual word, a model of car or a name, a person begins to see it all the time. The linguist Arnold Zwicky coined the term frequency illusion, and the Oxford English Dictionary later added it. The word illusion carries the claim. What rises is the count in the mind, not the count in the world, and the impression is strong enough to feel like a measurement.
Zwicky introduced the term in a post on the Language Log blog dated 7 August 2005, titled Just Between Dr. Language and I. The post was about language, and the frequency illusion has kept a home there: a reader meets an unfamiliar word or construction once, then spots it in the next article, in a song and in a stranger's email. The dictionary defines it as a quirk of perception in which something newly noticed seems to be everywhere.
Zwicky called it a selective attention effect: once people notice something, they register nearly every instance that crosses their path, and their estimates of its frequency drift upwards. His example was the quotative use of the word all, which was said to be constant in the speech of some of his students' friends and turned up rarely in recorded and transcribed conversation.
Only the Feeling Is New
Three separate things happen in the experience, and only one of them is a change.
- Something is noticed for the first time, which can be as small as an unfamiliar word.
- The same thing turns up again soon afterwards. In most cases it was already in circulation before anyone paid attention to it.
- The person feels the thing has become frequent. Only this step is new, and it happens in the observer, not in the world.
That is the sense of illusion in the term. A frequency illusion is a mistake about how often something occurs, produced by a change in what a person registers. The mistake is easy to make because both counts are kept in the head. Few people keep a tally of the words they read last month, so the first sightings after learning a word stand out against a past that was never recorded. The comparison is between a vivid recent sample and a blank earlier one.
Daniel Kahneman's Thinking, Fast and Slow gives the general version of this problem under the label WYSIATI, short for what you see is all there is. In Kahneman's account the fast system builds the best available story from whatever information is active at the moment and does not register what is missing. Applied to the frequency illusion, the sightings that come to mind are the whole record, and the earlier years in which the word passed unnoticed are not part of it.
Attention Does the First Part
Zwicky's description ties the illusion to selective attention, the ability to favour some inputs and leave others unprocessed. The listening experiments of the 1950s showed how much goes unprocessed. Colin Cherry's 1953 work on following one voice among several set the problem, and Neville Moray reported in 1959 that a listener's own name could break through from a message the listener had been told to ignore. The follow-up studies on names are covered in Why You Hear Your Name in a Crowd, and the original experiments are set out in What is the cocktail party effect.
A name is not louder than the other words in an ignored message. It has become personally relevant, and relevance changes what is registered. A newly learned word works in a similar way. Before it was learned, it had nothing to attach to and passed without remark. Afterwards it can be recognised, so it is registered each time it appears. The change is in the filter, not in the supply of words. Carrying the finding from names in a listening task over to newly learned words is an inference from the attention literature and not something those experiments tested.
Attention is steered by expectation as well. Raymond Nickerson's review of the evidence on confirmation bias, published in Review of General Psychology in 1998, collects experiments in which people noticed and remembered information that fitted what they already believed, often without intending to. Mock jurors, for example, recalled statements that fitted their chosen verdict as having been presented, including some that never were. A person who has begun to suspect that something is turning up everywhere stands where those observers stood: each sighting counts in its favour, and each day without one leaves no record.
Ease Passes for Frequency
The letter experiment that opened this piece is the cleanest demonstration of the step from this comes to mind easily to this is common. The authors explained the result by ease: words that begin with a letter are easier to bring to mind than words with that letter in third place, and the ease was taken as a sign of how often the letter occurs. Their second experiment used lists of names in which one group of names was famous. Of 99 participants who judged whether a list held more men or more women, 80 named the group that contained the famous names, which was the less numerous group.
Both results show frequency being judged from how readily instances arrive. After a word is learned, instances of it arrive readily, because for that reader the word has become well known in the sense of the experiment. The estimate of how often it occurs rises with that familiarity, whatever a library of texts would show. Kahneman's book presents the availability heuristic as a swap of an easy question, how quickly examples come to mind, for a harder one, how common the thing is. How that swap is put to work in advertising is followed in Does the Availability Heuristic Sell.
Checking Against a Record
A record can settle a doubt that an impression cannot. A dated archive, a search of a text collection or a log begun on the day of the first sighting gives a count that does not depend on what was noticed. If the frequency has really risen, as with a word that enters wider use after a news event, the record will show it, and the illusion is not the explanation. If the record is flat, the change was in what the observer registered.
The test is a practical suggestion and not a finding from any of the studies above. What the studies do supply is the reason it is needed: attention decides what is logged, expectation decides what counts as a hit, and ease of recall decides how common the thing seems. An independent count removes all three at once.
Common questions
What is the Baader-Meinhof phenomenon?
It is the popular name for the frequency illusion, the impression that something you have just noticed is suddenly appearing everywhere. The term frequency illusion was coined by Arnold Zwicky in 2005, and the Oxford English Dictionary added it in 2019.
Is the frequency illusion a real effect?
The experience is widely reported, and the frequency illusion names a mistake about how often something occurs. The processes linked to it, selective attention, confirmation bias and judging frequency by ease of recall, each have experimental support. The link between those processes and everyday sightings is an inference.
How can you tell a real increase from the frequency illusion?
Compare against a dated archive or a count that was started independently of your own sightings. A rise in the record means the world changed; a flat record points to a change in what was registered.
Sources
Zwicky, A. (2005). “Just between Dr. Language and I.” Language Log, 7 August 2005. https://languagelog.ldc.upenn.edu/myl/languagelog/archives/002386.html
Zimmer, B. (2019). “Frequency illusion in the OED.” Language Log. https://languagelog.ldc.upenn.edu/nll/?p=42180
Cherry, E. C. (1953). “Some experiments on the recognition of speech, with one and with two ears.” Journal of the Acoustical Society of America, 25, 975-979. doi:10.1121/1.1907229.
Moray, N. (1959). “Attention in dichotic listening: affective cues and the influence of instructions.” Quarterly Journal of Experimental Psychology, 11(1), 56-60. doi:10.1080/17470215908416289.
Nickerson, R. S. (1998). “Confirmation bias: A ubiquitous phenomenon in many guises.” Review of General Psychology, 2(2), 175-220. doi:10.1037/1089-2680.2.2.175.
Tversky, A., & Kahneman, D. (1973). 'Availability: A heuristic for judging frequency and probability.' Cognitive Psychology, 5(2), 207-232. doi:10.1016/0010-0285(73)90033-9
Kahneman, D. (2011). Thinking, Fast and Slow. Farrar, Straus and Giroux. Seed book; vault hub Books/Thinking Fast and Slow.