Mass psychogenic illness in organizations: An overview

Published and unpublished reports of mass psychogenic illness, defined as the collective occurrence of physical symptoms and related beliefs among two or more persons in the absence of an identifiable pathogen, are reviewed with particular emphasis on organizationa l occurrences. A number of factors (e.g. boredom, sex-role identification, interpersonal conflict, physical stress) are identified as potential precipitating conditions, and the contagion of symptoms is discussed in terms of the convergence-contagion dichotomy in collective behaviour suggested by Milgram & Toch (1969). There is some evidence to indicate that the actual occurrence of contagious psychogenic illness in organizations is more frequent than the available literature would suggest (CoUigan & Smith, 1978). In the past, the underreporting of this phenomenon may be attributed to the fact that outbreaks of such illness are typically investigated by teams of industrial hygienists and medical professionals whose primary concern is the possibility of toxic exposure. The results of these investigations are then summarized in internal staff reports for limited distribution. Should environmental tests and medical evaluations prove inconclusive, a suggestion may be made that psychogenic factors played a contributory, if not primary, role in the aetiology of the illness. This conclusion is based more on the absence of a clearly identified pathogen than the presence of well-defined psychosocial precipitating factors. Unfortunately, merely labelling the phenomenon as 'psychosomati c' or 'anxiety induced' does little in promoting an understanding of the dynamics of the illness. The present paper draws upon published and unpublished reports about contagious psychogenic illness in organizations . Sixteen studies are analysed in detail, of which seven involve work environments and nine involve school settings. These organizational studies may be viewed as complementary to investigations of such illness outbreaks in larger communities (e.g. Fallaize, 1923; Halliday, 1948; Yap, 1952) which are beyond the scope of the present review. Table 1 presents summary descriptions of these investigations. The original reports vary considerably in terms of thoroughness and the nature of the data presented. In fact, the absence of a consistent and systematic data base has been one of the major impediments to a current understanding of this phenomenon. Nevertheless, it is hoped that sufficient information may be derived from these admittedly sketchy reports to provide direction for future research in this important area.