collective hysteria
the spontaneous outbreak of atypical thoughts, feelings, or actions in a group or social aggregate. Manifestations may include psychogenic illness, collective hallucinations, and bizarre actions. Instances of epidemic manias and panics, such as choreomania in the Middle Ages, tulipmania in 17th-century Holland, and radio listeners’ reactions to the Orson Welles broadcast based on H. G. Wells’s War of the Worlds in 1938, have been attributed to collective hysteria. Also called group hysteria; epidemic hysteria; mass hysteria.