UNDER THE MICROSCOPE:THE SKIN-COVERING ordinarily reserved for rational social behaviour is surprisingly thin – remember the "moving statues" phenomenon in the summer of 1986. The latter is commonly explained as a form of mass hysteria. But history provides many examples of far more serious mass outbreaks of bizarre behaviour, apparently precipitated by a mixture of distress and pious fears. There is now compelling evidence that these outbreaks were instances of mass psychogenic illness. The story of this bizarre behaviour is described by John Waller in The Psychologist, in July.
In 1374 hundreds of Rhine Valley villagers were seized by a compulsion to dance for days in succession, scarcely pausing to eat. This dancing mania spread to north-eastern France and to the Netherlands, lasting for several months. Sporadic outbreaks of dancing mania occurred in the 1400s throughout Europe and an explosive instance occurred in 1518 in Strasbourg involving 400 people, causing dozens of deaths.
Waller describes another strange phenomenon in 1491 in a Dutch nunnery when several nuns were “possessed by devils” who made them run around barking like dogs, claw their way up trees like cats or launch themselves out of trees like birds. Such instances occurred regularly around Europe over the next 200 years, mostly, but not exclusively, in nunneries. Nuns would foam at the mouth, scream, sexually proposition priests and exorcists, and claim to have had carnal relations with devils, or with Christ.
Contemporary observers believed that such strange behaviour was a sickness. In recent times there has been a tendency to offer a biological explanation, principally that such epidemic episodes were caused by the ingestion of a mould called ergot that contains psychotropic chemicals. However the current consensus of psychology, history and anthropology explains these outbreaks as mass psychogenic illness (MSI).
The participants in these bizarre outbreaks seemed to be in the grip of a dissociative trance, which causes dramatic loss of self-control. Ergot could induce hallucinations and convulsions but, in Waller’s opinion, is extremely unlikely to precipitate relentless dancing. However, there is considerable evidence that communities that suffered such epidemic outbursts were also under severe physical and psychological stress. As Weller explains, since there is a well established link between psychological stress and dissociation, this immediately suggests MSI.
For example, the years before the 1374 outbreaks witnessed the worst flooding of the Rhine Valley in centuries and, in the decade before the 1518 dancing plague, famine, sickness and savage cold ravaged Strasbourg. Nunneries could also become “toxic psychological environments”. Young women were often sent there to satisfy parents’ wishes rather than any wish or pious disposition on their own part. Many were consumed by guilt at failing to meet the standards of holiness demanded by their Orders and terrified themselves with the Hell fire awaiting those harbouring impure thoughts.
The culture of the time believed that possession by devils, leading to convulsions, lewd behaviour, and so on, was a real possibility. Waller proposes a psychological explanation for these bizarre epidemics – believing in the possibility of possession, people made themselves susceptible to it and succumbed when stress became intolerable. The dancers of 1374 believed that a devil had placed a dancing curse on them.
MSI remains with us today, taking various forms, depending on local culture. Waller describes periodic epidemics among men and women in southeast Asia of a fear that their genitals are shrinking into their bodies under the influence of an evil spirit. Death is believed to ensue once the genitals fully disappear. Men have been known to drive pegs through their penises to prevent complete retraction!
More mundane cases of MSI are not uncommon. For example, a 1955 epidemic of headache, sore throat, nausea, vomiting and diarrhoea at London’s Royal Free Hospital is now cited as a case of MSI. At the time, microbiologists found no bacteria to blame and put the cause down to an unidentified virus.
However, recent analysis of the case noted that 11 per cent of the women affected displayed severe symptoms compared with 0.8 per cent of the men, and most of the victims were nurses under 30. This pattern is similar to other MSI epidemics in hospitals where most of the victims are female. No victim died or even had a high fever, most unlikely in an infectious epidemic. On the other hand there was an outbreak of polio in the area which spread fear in the hospital population. The anxiety was self-propagating leading to mass hysteria.
Drs Colin McEvedy and Alfred Beard analysed the case in The British Medical Journal, Vol.1, (1970), saying, ". . . the hysterical reaction is part of everyone's potential and can be elicited in any individual by the right circumstances. A mass hysterical reaction shows not that the population is psychologically abnormal, but merely that it is socially segregated and consists predominantly of young females."
William Reville is associate professor of biochemistry and public awareness of science officer at University College Cork: understandingscience.ucc.ie
