The Convent Biting Mania

MASS HYSTERIA is the shallowest drawer in my mother’s steel cabinet, yet the folders inside are among the most densely packed. Today, I pulled a thin, blue-tabbed folder labeled simply: 1491 — The Biting Mania. Inside, she had compiled several chapters from nineteenth-century medical histories alongside modern psychological analyses of mass psychogenic illness.

The narrative of the biting mania is a classic, if highly disputed, cornerstone in the study of shared delusions. The year 1491 is frequently associated with these outbreaks of “possession” in convents across the Spanish Netherlands and surrounding regions. According to the standard account, the phenomenon began with a single nun in a German cloister who began biting her companions. Within a short period, this behavior allegedly spread “from cloister to cloister,” moving through Germany, into the Netherlands, and eventually reaching as far south as Italy.

The primary vehicle for this bizarre history is the work of Justus Friedrich Karl Hecker, a nineteenth-century German physician. In his 1844 compilation, The Epidemics of the Middle Ages, Hecker presents the biting mania as a historical certainty. He, along with other early writers, frequently cited the sixteenth-century physician Girolamo Cardano—often referred to as Cardan—as an early authority who observed and documented this violent, involuntary behavior. According to these accounts, the contemporaries of these nuns initially interpreted the biting as a form of demonic possession, attempting to cure it through elaborate exorcisms. When spiritual remedies failed, the authorities turned to more secular, coercive measures. The mania was reportedly brought to a halt only when external officials threatened the afflicted women with severe corporal punishment, specifically whipping and flogging.

As a historian, I find the academic consensus on this event far more revealing than the sensationalized narrative. There are no known surviving fifteenth-century primary sources—no convent chronicles, no local trial records, no contemporary letters—that specifically detail a “biting” epidemic in 1491. Instead, modern researchers suggest that the biting mania is likely an anecdotal generalization or a later conflation. During this period, there were indeed documented “possession” epidemics in European convents, but these involved other expressive, non-verbal behaviors, such as nuns meowing like cats or climbing into the branches of trees. Over the centuries, these distinct events were likely compressed by later writers into a single, dramatic trope of physical violence.

My mother had photocopied several pages of Hecker’s text, focusing on the section describing the “unaccountable impulse” that supposedly drove the first nun to strike. In the wide margin, her neat handwriting offered a quiet, sober assessment: They did not bite because they were devils. They bit because they had been stripped of every other language. If you build walls thick enough, the teeth will eventually find a way to speak.

It is 02:12 AM now. The house has settled into its late-night stillness, though a faint, rhythmic vibration is hum-clicking behind the plaster of the desk wall, like the rapid, distant strike of typewriter keys against paper. The air in the study is perfectly still, but it carries a thin, dry smell of old copper. I will shut the drawer and leave the blue folder on the blotter.

I am sending this to Lukas over the line. If it only exists here, it doesn’t exist.

>>> BEGIN CAPTURE
FILE MASS_HYSTERIA/1491/CON-306
SUBJECT: the biting mania of 1491
---
folder contains nineteenth-century medical histories.
modern psychogenic illness analyses included.
narrative traces to 1491 in a German cloister.
alleged spread through Germany, Netherlands, to Italy.
primary source is Justus Friedrich Karl Hecker, 1844.
Hecker cites sixteenth-century physician Girolamo Cardano.
secular authorities halted mania with threats of whipping.
no surviving fifteenth-century primary sources exist.
no convent chronicles or trial records confirm biting.
documented epidemics involved meowing or tree climbing.
---
M. NOTE:
They did not bite because they were devils. They bit because they
had been stripped of every other language. If you build walls
thick enough, the teeth will eventually find a way to speak.
>>> END CAPTURE