According to one of the most frequently repeated stories in the history of mass hysteria, a single nun in a medieval French convent began meowing like a cat, and within days her entire convent was gathering every afternoon for hours of collective, ear-splitting caterwauling until soldiers were sent in to whip the sisters into silence. It's one of the most vivid images in this entire series, and one of the shakiest, since the closer historians look at where the story actually comes from, the harder it becomes to find any real convent, date, or original source behind it at all. Its lesser-known companion case, a documented outbreak of nuns biting one another across several German, Dutch, and Italian convents in the 15th century, turns out to rest on considerably firmer historical ground.
Background: A Genre Convents Were Prone To
Convents across medieval and early modern Europe were, structurally, almost a perfect match for the conditions researchers now associate with mass psychogenic illness: closed, socially isolated communities of young women living under strict discipline, intense religious pressure, and little outside contact. Several genuinely documented outbreaks of convulsions, screaming fits, and supernatural conviction occurred in convents across this period, of which the Loudun possessions covered earlier in this series are the most thoroughly recorded example.
The meowing nuns story and the biting nuns story both circulate as part of this broader genre, but they arrived in the historical record very differently, and that difference matters enormously for how much weight either deserves today.
One Story on Shaky Ground, One on Firmer Footing
The meowing nuns tale is almost always traced back to the 1844 English translation of German physician Justus Hecker's book "The Epidemics of the Middle Ages." But historians examining the original text closely have found that the anecdote doesn't actually appear in Hecker's own writing at all. It appears only in a footnote added by the book's English translator, Benjamin Guy Babington, who cited it as something he had "read in a good medical work," without naming the work, a date, a location, or any verifiable original source. No earlier medieval or early modern document describing the incident has ever been located.
The biting nuns case rests on noticeably better documentation. A detailed contemporary account, attributed to a 15th-century physician and repeated across multiple historical sources, describes a nun in a German convent who began biting her companions, with the behavior then spreading convent to convent across Germany, chiefly Saxony, before reportedly reaching convents in the Netherlands and eventually Rome. Church authorities, believing the nuns to be possessed, attempted exorcisms that failed to stop the behavior; what finally ended it, according to the sources, was the threat of flogging or being dunked in cold water, along with, some accounts suggest, the outbreak's own gradual exhaustion.
Two Convent Legends Compared
| Case | Claimed Era | Source Quality | Behavior | How It Reportedly Ended |
|---|---|---|---|---|
| Meowing Nuns of France | Undated, medieval | Weak; traced to an unsourced 1844 translator's footnote | Collective daily meowing sessions | Soldiers threatened whipping |
| Biting Nuns of Germany | 15th century | Stronger; contemporary physician account, cross-referenced across convents | Nuns biting one another, spreading convent to convent | Threat of flogging or dunking; failed exorcisms |
| Loudun Possessions | 1632–1638 | Strong; extensive trial records and later scholarship | Convulsions and claimed demonic possession | Political intervention ended public exorcisms |
| Tanganyika Laughter Epidemic | 1962 | Strong; contemporary school and medical records | Uncontrollable laughing fits | School closures interrupted transmission |
Theories & Explanations: Why One Story Survived Without Evidence
A vivid image travels further than a careful citation. The meowing nuns story is memorable, visually specific, and fits neatly into an existing genre of convent hysteria tales, which historians studying its spread have argued is more than enough to explain its durability across nearly two centuries of retelling, regardless of whether it ever happened.
Popular science writing rarely traces sources back to their origin. Because the tale has been repeated across countless books, articles, and lists of "history's weirdest mass hysteria cases" without anyone re-checking Babington's original, unsourced footnote, each retelling has effectively borrowed credibility from the sheer number of previous retellings rather than from any actual historical document.
The biting nuns case survived scrutiny specifically because it has real anchors. Unlike the meowing story, the biting outbreak is described by a named class of source, a contemporary physician's account, cross-referenced across multiple regions and later historical works, giving researchers actual textual evidence to evaluate rather than a secondhand claim about an unnamed source.
Convent-based contagion, when genuinely documented, follows the same pattern seen throughout this series. Isolated, stressed, tightly bound communities under religious pressure recur again and again in genuinely verified cases, from the German biting nuns to Loudun, suggesting the underlying mechanism is real even in the specific case where its most famous illustration probably isn't.
The Curious Connection
Placed side by side, these two convent stories illustrate something this entire series has to reckon with directly: mass psychogenic illness is a genuine, well-documented phenomenon, but the folklore surrounding it is not automatically trustworthy just because it sounds historically plausible. The meowing nuns story earns its place in this series not as confirmed history but as a case study in how a single unsourced footnote can travel almost two centuries and end up cited as fact in article after article, exactly the kind of uncritical repetition this series has tried to push back against with every previous entry.
The biting nuns case, by contrast, shows what genuinely well-sourced convent hysteria looks like, and stands as a useful control against which more suspect legends, like its meowing counterpart, can be measured.
Frequently Asked Questions
Did the meowing nuns of France really exist?
There is no verified original source. The story is traced to an unsourced footnote added by the English translator of an 1844 German medical history book, and no earlier document naming a specific convent, date, or location has ever been located.
Is the biting nuns case more credible?
Yes. It rests on a contemporary account attributed to a 15th-century physician, describing an outbreak that spread across multiple named regions, Germany, the Netherlands, and reportedly Rome, and it is cross-referenced across several historical sources rather than a single unsourced footnote.
Why do both stories keep getting repeated as fact?
Both fit a vivid, memorable genre of convent hysteria tales that has been repeated across countless popular history articles without each writer tracing the claim back to its original source, allowing an unverified anecdote to accumulate the appearance of established fact.
How did the biting nuns outbreak reportedly end?
Church authorities first attempted exorcisms, believing the nuns were possessed, which failed to stop the behavior. Sources describe the outbreak finally ending after threats of flogging or being dunked in cold water, along with what some accounts suggest was the episode's own gradual exhaustion.
What does this pair of stories add to the study of mass psychogenic illness?
It's a reminder that verifying sources matters as much as identifying the underlying psychological pattern, since even a well-established field of genuine research can end up carrying along at least one famous case that may never have actually happened.