Last Friday, Oliver Burkeman of The Guardian published a pretty interesting piece about the influence of mind over body in relation to personal health and biology. He pitched the case study of imagined genital retraction that had affected hundreds of men across nations and cultures, all of whom believed the same thing — their penises (or is it peni, as in octopi?) were vanishing.

Even more interesting was the fact it’s all true, especially about that sordid period of time when hundreds of Singaporean males rushed themselves to hospitals in 1967 with their dicks firmly gripped in hand in fear of their manhoods shriveling into their bodies.

If hands weren’t believed to be secure enough, some arrived with their knobs twirled around chopsticks or secured with clothes pegs. Others simply wrapped their shafts with red string, as a form of auspice against supernatural shrinkage. We’re not making it up — it’s a well documented affair that not many younglings may know about (it’s not exactly Social Studies material). Folks need to know about this prick-ly issue dammit, so here’s an explainer.

Koro: The imaginary mongoose to the one-eyed trouser snake

Yes, this syndrome has a name, and it’s commonly called ‘Koro’ in Asia or simply ‘genital retraction syndrome’ in the Western world. It’s defined as a culture-specific syndrome (AKA folk illness) where individuals have the genuine belief that their genitalia are retracting, and will eventually disappear.

It’s not a permanent thing however (the syndrome, not the penis), as it’s more of a sudden episode of anxiety that the penis will recede into the body and quite possibly cause death. Though Koro has been notably present among African and European nations, it’s more common in Southeast Asia, predominantly among the Chinese diaspora.

It’s all in the head of course. Those infected with Koro don’t really have visible biological changes in their genitalia (unless it’s cold… because it does shrink), but victims can have a perception of retraction that could last from hours to days, and in some cases, even years. Asians typically believe that going dickless is fatal — and as such, will respond with brute force like clamping hard on their manhoods, to the point of injury.

Women aren’t excluded in Koro however. The female version sees women having anxieties over retracting vulva and nipples. Similarly, they’d respond with brute force as well to prevent imaginary shrinkage from happening — some cases involve women inserting iron pins into their nipples, not unlike piercings. Just less sterilisation and more bloody.

The Asian persuasion

It is not known where the original belief of shrinking genitalia arrived from, but it seems to be rooted in East Asian culture. The word ‘Koro’ itself is believed to have originated from the Malay word for turtles, ‘Kura-kura’. A crude yet apt analogy — retracting dicks in comparison to how turtles retract their head into their shells. Among the Chinese however, the phenomenon is commonly known as ‘Shook Yong’, bluntly meaning “the shrinkage of penis”.

Koro hysteria was still widespread though, even if it was a mainly Asian thing. Since word of the phenomenon got out into the Western hemisphere, cases of Koro were occasionally reported in places such as Canada, Jordan, France, Britain, and even Nigeria, where people were actually killed on suspicion of using magic to make dicks disappear.

For some reason, Koro is more established in Southeast Asia, where most of its victims seem to be of Chinese origin, even if they live in Malaysia or Indonesia. It could very well be folktales, but no-one can specifically point out what exactly folks are telling their children to make them fear perishable peckers.

So what happened in 1967?

Singapore has remained a notable highlight in the record books of genital retraction syndrome after a particularly severe nationwide epidemic in 1967.

For weeks in October and November that year, an alarming rumour went viral — one that stated that Koro was caused by eating the flesh of pigs that were recently vaccinated in a mass campaign to combat swine fever. The rumour snowballed to the point where the sale of pork in markets, stalls and restaurants stood at a standstill.

Usually limited to only one or two cases in a lifetime, general practitioners were then hit by an average of 70 to 80 cases a day. They arrived by the dozens, holding on to their penises with hands, rubber-bands, strings, clothes pegs and other household utensils (that hopefully they never re-used again).

Here’s a description of one such case, extracted from the British Medical Journal of 1968:

“A typical case was that of a 16-year-old school boy who dashed into the clinic with his parents shouting for the doctor to attend to him quickly because he had ‘Shook Yong’. The boy looked frightened and pale and he was pulling hard on his penis to prevent the organ from disappearing into his abdomen.

The doctor explained and reassured both parents and patient. A tablet of 10 mg of chlordiazepoxide was given at once and he was sent home with two days’ supply of chlordiazepoxide. There was no recurrence.

The boy had heard about Koro in school. That morning he took ‘Pow’, which contained pork, for breakfast. Then he went to pass urine and noticed his penis shrunk at the end of micturition. Frightened, he quickly grasped the organ and rushed to his parents shouting for help.”

It seems pretty clear that it’s all just imagination enhanced by fears after first hearing about Koro. Majority of the cases were found among people younger than 20 years of age — and where children were affected, it was usually due to a mother’s anxiety. Most victims of the epidemic were Chinese, though there were some isolated cases of other ethnic groups getting into hysterics as well.

The main cause was summed aptly up as such:

“All had previous knowledge of Koro. The onset usually followed a normal physiological cause of retraction and shrinking of the organ — for example, after a bath, after passing urine, after illnesses, etc.”

Be that as it may, the epidemic was severe enough that the Singapore Medical Association and the Ministry of Health had to allay fears in multiple press conferences. Major lulz were presumably had in the aftermath of it all, and Singaporeans went about their business without worrying about their peckers and nipples shrinking away into oblivion.