In the 14th century, one of the earliest instances of mass hysteria occurred. The story was recorded in a 19th century book titled Epidemics of the Middle Ages, by J.F.C Hecker which drew on various medieval texts. 

 

The incident’s details are as follows. A group of nuns in a French convent suddenly began meowing like cats for hours every single day. Their wild and uncontrollable behavior quickly spread throughout the convent, and many people believed this was a form of possession. The situation only came to an end when the nuns were threatened with being whipped by local soldiers. 

 

Drawing on research of mass hysteria, it is clear that the nun’s environment in the 1400s was an excellent breeding ground for mass psychogenic illness. Nuns were often forced into convent life, resulting in high stress and fear within their environment.