Collective hysteria

Collective hysteria, or mass hysteria, is the sociopsychological phenomenon of the manifestation of the same hysterical symptoms by more than one person. It may begin when a group witness an individual becoming hysterical during a traumatic or extremely stressful event. A potential symptom is group nausea, in which a person becoming violently ill triggers a similar reaction in other group members.

Examples include certain cases of rioting and frenzy, and accidents in which people act "irrationally" (screaming, running in the wrong direction, etc.).

Writer Jerome Clark&mdash;while recognizing that mass panic can undoubtedly be genuine and widespread&mdash;argues that mass hysteria can be "a classic blame-the-victim strategy" in cases where authorities or experts can find no explanation for puzzling or frightening events.

Depending on one's personal beliefs, the phenomenon can also be theorized to be described in certain religious contexts, such as the Pentecostal outpouring of the Holy Ghost described in the Book of Acts.