The rarest fetishes, and whether anyone has them

Search for the rarest fetishes and you get a list of Greek words, each with a one-line gloss and no evidence behind it. Nothing on the list says which of the words describe anyone. A term such as climacophilia, arousal from falling down stairs, looks as solid on the page as foot fetish, and a reader cannot tell that one rests on a 381-group study and the other on a line in a textbook glossary.

The catalog can tell the difference, because every entry carries its sources and a confidence rating for its numbers. At the bottom of the index the useful question is whether anybody has ever been found who has the interest. Sorting the tail by that question gives three different kinds of rare. They are the words, the cases and the communities, and each needs a different kind of scepticism.

Where the rare names come from

Most rare fetish names were coined in clinical and forensic books and then copied from list to list. Richard von Krafft-Ebing set the pattern in Psychopathia Sexualis in 1886, naming sexual variations from the case histories he collected. The names came with patients attached.

The sexologist John Money kept the Greek naming habit and multiplied it. With Gregg Furth he named apotemnophilia, the wish to become an amputee, in 1977. His 1984 paper Paraphilias: Phenomenology and Classification added symphorophilia, arousal from disasters, and his 1986 book Lovemaps added autassassinophilia, the staging of one's own killing. Twenty-two entries in the catalog name Money in their etymology.

The largest list of all is the one its author warned about. In 2008 the forensic physician Anil Aggrawal compiled 547 paraphilic terms in Forensic and Medico-legal Aspects of Sexual Crimes and Unusual Sexual Practices, and cautioned that "not all these paraphilias have necessarily been seen in clinical setups." Wikipedia's list of paraphilias draws heavily on that compilation, and the listicles draw on Wikipedia, mostly without the caution.

The bottom of the index

The index puts 131 of its 486 entries in the two lowest tiers. It rates 96 as rare, an estimated 0.05 to 0.5 percent of adults, and 35 as very rare, under 0.05 percent. All 131 carry a low confidence rating. The methodology defines low confidence as anecdotal or proxy-only evidence: the number is an order-of-magnitude guess.

Entry	Index	Estimated prevalence	Research attention	Community size
Cenophilia	2	0.01%	3	2
Cacophilia	2	0.01%	4	3
Timophilia	2	0.01%	3	2
Wood fetish	2	0.01%	2	3
Smegma fetish	2	0.01%	1	4

The last two columns are two of the four behavioural signals the index scores on 0 to 100 beside prevalence. Research attention measures how much the literature has written about an interest. Community size measures how many people gather around it. At the bottom of the index both run near zero, and where they part, they show which kind of rare an entry is.

Twenty-two of the 35 very rare entries sit in the clinical paraphilias family. Several of those are there because the harm defines them, and the catalog documents them for that reason. Necrophilia and erotophonophilia are rare and well studied, mostly by forensic researchers working from criminal cases. Their research attention runs to 58 and 55.

Words with nobody behind them

The rarest entries by score are terms without a documented person. Cenophilia joins the Greek kenós, "empty", the root of cenotaph, to -philia and glosses it as arousal from empty spaces. No coiner, no date of first use and no clinical case are recorded. Cacophilia, from kakós, "harsh", the root of cacophony, traces to a single line on page 78 of Aggrawal's book.

The sourcing thins further down the list. Climacophilia reaches Wikipedia through a glossary in Eric Hickey's 2006 textbook Sex Crimes and Paraphilia. The source for antholagnia, arousal from the scent of flowers, is a glossary website entry from 2015. Jactitation borrows a medical word for the restless tossing of a fever patient and gives it an erotic sense that no named author ever claimed.

For these terms the catalog documents a word, and the estimated prevalence of 0.01 percent is a floor the index assigns to something no survey has measured. The entries say so in their first sentence. We keep them because readers search for them, and the entry is the place to say how little is known.

Interests known from a single case

A smaller group of rare interests have real people on record, often one person each. Formicophilia, arousal from small creatures crawling on the skin, was named in 1986 by Ratnin Dewaraja and John Money in the Journal of Sex & Marital Therapy. It came from one young man in Sri Lanka who had started collecting ants at about the age of nine. A follow-up in 1987 described his treatment, and a second case, involving fire ants, was presented in 2012. The whole literature of formicophilia is about three papers long.

Symphorophilia and autassassinophilia have the same shape: a name from Money, a clinical description and little literature after it. Their research-attention scores of 34 and 48 sit far above their prevalence. Research attention counts how often a term is written about, and reviews and textbooks repeat a coined term whether or not anyone reports a new case.

The exception is the desire for amputation, where somebody went and counted. Michael First's 2005 study in Psychological Medicine interviewed 52 people who wanted a healthy limb removed. Only 29 percent reported sexual arousal as a motive. Most described a body that felt wrong, and 41 of the 52 had no psychiatric symptoms. The catalog files the erotic form as apotemnophilia and the identity form as body integrity dysphoria, which ICD-11 codes as 6C21.

Communities the journals missed

Some rare interests have a community and no literature. Petrification fetish, the fantasy of being turned to stone, scores 22 for community size and 4 for research attention. Dronification scores 28 and 8, body inflation 22 and 8, and sneeze fetish 18 and 8. These interests have art, forums and their own vocabulary. They have no Greek name, because nobody has written them up.

The gap follows from how the two kinds of evidence are produced. A clinical term needs a patient who came to a clinician, which usually means distress, a crime or a court. A community needs only people who share a fantasy and found each other online, and none of them has to come anywhere near a clinic. Scorolli and colleagues' 2007 study of 381 online fetish groups measured this second kind of evidence, and it is one reason foot fetish has a reliable number and cenophilia does not.

On community size, these interests leave more trace than most of the Greek terms above them in the listicles. They sit low in the index because no survey has asked about them.

The rarest fetish that never happened

Oculolinctus, eyeball licking, owes its fame to a news story that turned out to be false. On 7 June 2013 a Japanese subculture site reported that the practice had become a craze among schoolchildren, on the word of one anonymous teacher. English-language outlets repeated it within days.

The Tokyo journalist Mark Schreiber traced the story to that single source and found no medical body aware of any outbreak. In August 2013 the Guardian withdrew its coverage, and Snopes rated the trend fake. The word came out of the episode better known than any documented case of the interest it names. The best-sourced facts in the entry are the hoax itself and the eye-health risks that ophthalmologists described at the time.

What rare means to a researcher

A survey counts a fantasy as statistically rare when 2.3 percent of respondents or fewer report it. In Joyal, Cossette and Lapierre's 2015 study of 1,516 adults and 55 fantasies, only two fantasies met that threshold for women or men, and nine more counted as unusual at 15.9 percent or fewer. General-population surveys are too coarse to see the bottom of the index: an interest held by one adult in 10,000 would not show up in a sample of 1,516.

Rarity is not a diagnosis either. Neither DSM-5-TR nor ICD-11 names cenophilia, climacophilia or formicophilia. A rare interest becomes a clinical matter only when it causes distress, impairment or harm, and then it falls under the residual heading of other specified paraphilic disorder. The threshold is the same one that applies to a common kink, and is my kink normal sets it out.