Quotes from Laurie Winn Carlson

more modern version of the hysteria complex is called Mass Psychogenic Illness, or MPI, which is defined as the contagious spread of behavior within a group of individuals where one person serves as the catalyst or "starter" and the others imitate the behavior.

The Salem Witchcraft Papers,

by Paul Boyer and Stephen Nissenbaum.

Thomas Szasz, writing in The Manufacture of Madness, points out that this "human tendency to embrace collective error—especially error that threatens harm and commands specific protective action—seems to be an integral part of man's social nature.