What are the causes and effects of the phenomenon known as ‘mass hysteria’?

Mass hysteria, also known as collective hysteria, is a phenomenon that has puzzled and fascinated people for centuries. It is a state of intense emotional and psychological distress that occurs within a group of people, often resulting in irrational behavior and beliefs. Throughout history, there have been countless cases of mass hysteria, ranging from outbreaks of dancing mania in medieval times to modern-day episodes of social media-fueled panic. This phenomenon has had significant effects on individuals, communities, and even entire societies, making it a topic of great interest for researchers and psychologists. In this essay, we will explore the causes and effects of mass hysteria, shedding light on this fascinating and complex phenomenon.

Mass hysteria—other names include collective hysteria, group hysteria, Mass Psychogenic Illness, or collective obsessional behavior—is the sociopsychological phenomenon of the manifestation of the same or similar hysterical symptoms by more than one person. A common manifestation of mass hysteria occurs when a group of people believe they are suffering from a similar disease or ailment.



Mass hysteria typically begins when an individual becomes ill or hysterical during a period of stress. After this initial individual shows symptoms, others begin to manifest similar symptoms, typically nausea, muscle weakness, fits or headache.

Sightings of religious miracles are often attributed to mass hysteria.


Specific examples

In 2007 near Chalco, a working-class suburb of Mexico City, mass hysteria resulted in a massive outbreak of unusual symptoms suffered by adolescent female students at Children’s Village School, a Catholic boarding-school. The afflicted students had difficulty walking and were feverish and nauseated.

In 2008 in Tanzania, about 20 female school pupils began to faint in a schoolroom, collapsing to the floor and losing consciousness, while others after witnessing this sobbed, yelled and ran around the school. A local education officer was quoted in news reports saying that such events are “very common here”.

In 2009 in Fort Worth, Texas, 34 people were sent to the hospital after they complained about having symptoms when they mistakenly thought they had been exposed to carbon monoxide.

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