Arithmomania
Vampires in European folklore are regularly given this trait, usually as an inability to walk past scattered seed or millet without tallying it. Throw the grain down and the creature has to stop and count. Arithmomania is a mental disorder, best understood as one of the ways obsessive-compulsive disorder expresses itself, in which somebody is driven to count what they do and what surrounds them. The folklore had the mechanism right centuries before anybody named it.
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What the counting looks like
The forms it takes are ordinary and relentless. Counting steps while climbing or descending stairs. Tallying the letters in words. Counting tiles on a floor or a ceiling, or lines on a highway. Touching an object a set number of times, a doorknob or a table. Repeating an action a specific number of times in order to avert a catastrophe the person perceives coming, which is the part that makes it a compulsion rather than a habit.
The counting is done aloud or in thought, and either counts.
When arithmomania builds a system
It can grow into something far more elaborate. Numbers get handed out to people, to objects, to events, and the point of the assignment is to work out what holds them together. Numbers get attached to past events, and the person then returns to those events over and over through the numerical value that stands for them. An action performed a particular number of times can be linked in this way to a particular satisfying event, which turns the counting into a private index of a life.
Where arithmomania turns up in fiction
Count von Count on Sesame Street counts everything and anything, which is the vampire folklore played for children. Inspector Franklin Jalbert, in Stephen King's 2024 novella Danny Coughlin's Bad Dream, has it.
Oliver Sacks says the counting is the surface
Merriam-Webster's medical dictionary illustrates arithmomania with a passage from Oliver Sacks's Awakenings, and it is the most useful thing written about the condition in any of the sources here.
Sacks puts the counting second, and the arrangement first:
The arithmomania is as it were the surface of a more fundamental compulsion, which has to do with order and disorder: the need to order, disorder, reorder, and the contemplation of order, disorder, new order. Arithmomania has to do with arithmetical order.
That reframes every example in the definition. Counting the stairs, tallying the letters in a word, touching a doorknob a set number of times: on Sacks's account none of those is about the number. They are about the arrangement, and the number is the form the arrangement happens to take because numbers are the most orderly things available.
It also explains why a specific count matters when no reason attaches to it. A person repeating an action a particular number of times to avert a catastrophe is not calculating a risk. They are completing a shape.
Where the word arithmomania comes from
The Online Etymology Dictionary dates the word to 1884 and takes it from the French arithmomanie, built on the Greek arithmos, number, and the French -manie. The Online Etymology Dictionary records arithmomaniac as the related form.
The suffix is the point of it. Mania in this vocabulary means a compulsion rather than a fear, which is why arithmomania sits in this catalogue as an entry about something the phobia words, Fear of Numbers among them, are not. Nothing is being avoided. Something is being done, repeatedly, and stopping is what is intolerable.
Told apart
Often confused with Arithmomania
- Fear of NumbersThey are opposites that share a subject. Arithmophobia fears numbers and avoids them; this one produces them compulsively as a way of managing something else.
- Fear of the Number 13Both attach significance to particular numbers, but a superstition assigns meaning to one number where this assigns values across people, objects and events systematically.
- Fear of GermsThe repeat-until-it-is-right structure is the same compulsion, with counting doing the work that washing does, and both aimed at averting a catastrophe.
Common questions
Questions about Arithmomania
- What does vampire folklore have to do with it?
- European folklore gives vampires the compulsion, and specifically the need to count seeds or grains of millet, which is why scattering them across a threshold was a recognised defence. The joke behind Sesame Street's Count von Count has several centuries under it.
- Is anything actually feared?
- No. The suffix is mania rather than phobia. What drives the behaviour is a compulsion to count, frequently in order to avert a catastrophe the person perceives.
- What forms does it take?
- Counting stairs, tallying the letters in words, counting tiles or highway lines, and touching objects such as doorknobs a specific number of times. The word itself dates from 1884, coined in French as arithmomanie.
- How does it become a system?
- By assigning values to people, objects and events to work out their coherence, with numbers attached to past events so the person revisits them through the value.
- Where does it appear in fiction?
- Count von Count on Sesame Street counts everything, which makes him a joke with several centuries of vampire folklore behind it, and Inspector Franklin Jalbert has it in Stephen King's 2024 novella Danny Coughlin's Bad Dream.
- What did Oliver Sacks say about it?
- That the counting is not the point. In Awakenings he describes arithmomania as the surface of a more fundamental compulsion to do with order and disorder, the need to order, disorder and reorder, and concludes that it has to do with arithmetical order. On that reading a person repeating an action a set number of times is completing a shape rather than calculating anything.
Added 2026-08-23 · Revised 2026-08-26
Nearby in the catalogue
Related entries
- Fear of NumbersTrouble holding certain jobs, trouble paying bills, trouble managing a budget. This is a fear whose damage arrives as administration, not drama.
- Fear of the Number 13Isador Coriat had the word in print by 1910. No manual carries it and no survey counts it, so the evidence is a habit of numbering: floors, decks, plates.
- Fear of GermsWilliam A. Hammond made the word in 1879 describing an OCD case of repeated hand-washing. It now names a specific phobia, which are treated differently.
- Fear of Friday the 13thThe 17 to 21 million figure traces to one Asheville organisation. Two airlines report no drop in travel, and Dutch insurers log fewer accidents on the day.
- Fear of Long WordsThe famous name for the fear of long words is a fifteen-syllable joke. The clinical form is sesquipedalophobia, and it has no cases behind it either.
- Fear of PalindromesThe word is a palindrome, built by reversing its own suffix. Two sources give two origins four years apart and neither names the person who did it.