Читать книгу Connected: The Amazing Power of Social Networks and How They Shape Our Lives - James Fowler - Страница 19

Everyone has experience with emotional contagion: we share a joke with a friend, we feel sad when a spouse cries, we rage against city hall with our neighbors, and we hug our kids tight when they’ve had a bad day. Yet one often overlooked aspect of all this sharing is that emotions spread not only to our friends but to our friends’ friends and beyond—even when we are not present. We are like a herd of buffalo quietly grazing on the plain until one of our neighbors starts to run. Then we start to run, and others start to run, and suddenly, mysteriously, the whole herd is barreling forward.

Epidemics of emotional states have been reported for centuries. They just have not involved laughter like the Bukoba outbreak. When emotions spread from person to person and affect large numbers of people, it is now called mass psychogenic illness (MPI) rather than the old-fashioned and more poetic epidemic hysteria. MPI is a specifically social phenomenon involving otherwise healthy people in a psychological cascade. Like a single startled buffalo within a herd, a single emotional reaction in one person can sometimes cause many others to feel the same thing, creating an emotional stampede.

There are two main types of MPI. In the pure-anxiety type, people may feel a variety of physical symptoms, including abdominal pain, headache, fainting, shortness of breath, nausea, dizziness, and so on. In the motor type, people may engage in hysterical dancing, pseudo-seizures, and—yes—laughing, though the actual feelings underlying these behaviors are fear or anxiety. Both types of MPI thus involve the same basic psychological processes.

Historical records of such phenomena date back to at least 1374, when, in close succession to the Black Death in Europe, “dancing manias” broke out. The first such manias occurred in what is now Aachen, Germany. As described by the German medical historian J. F. C. Hecker in his 1844 book The Epidemics of the Middle Ages, these consisted of people who “united by one common delusion, exhibited to the public both in the streets and in the churches the following strange spectacle. They formed circles hand in hand, and appeared to have lost all control over their senses, continued dancing, regardless of the bystanders, for hours together, in wild delirium, until at length they fell to the ground in a state of exhaustion. They then complained of extreme oppression, and groaned as if in the agonies of death.”¹¹ These people were obviously no happier to be dancing than the African schoolgirls were to be laughing.

In a bygone era, demons and witchcraft were often seen as causes of these symptoms, but today toxic chemicals and environmental contamination are the triggers subjects typically identify. Yet, while toxins do cause some outbreaks of physical illness, they do not cause outbreaks of MPI. The source of the problem, as well as the mechanism of transmission, is psychological. Individuals afflicted in these outbreaks, and many observers, are often reluctant to ascribe the symptoms to a psychological source, however.

A relatively recent example of MPI occurred at the Warren County High School in McMinnville, Tennessee. At the time, the school had 1,825 students and 140 staff members. On November 12, 1998, a teacher believed she smelled gasoline, which caused her to complain of headache, shortness of breath, dizziness, and nausea. Seeing her response, some of her students soon developed similar symptoms. As the classroom was being emptied, other students, observing what was happening, began to report feeling unwell too. A schoolwide fire alarm was activated, and the school was evacuated. The teacher and several students were transported by ambulance to a nearby hospital, in full view of other students and teachers who were outside because of the alarm. Large numbers of police, firefighters, and emergency medical personnel from three counties responded. A total of one hundred people went to the hospital that day, and thirty-eight were admitted. Classes were canceled.

The school was closed for four days. It was inspected by the fire department, the gas company, and state officials from the Occupational Safety and Health Administration (OSHA), but no problems were identified. After the school had been deemed perfectly safe, the students and the teachers were allowed to return. Unfortunately many still smelled odors, and on November 17, seventy-one people were stricken. Ambulances were again called, and the school was evacuated and then closed.

The school’s principal was fed up. In a “no more Mr. Nice Guy” move, he decided to call several government agencies, including the famed Epidemic Intelligence Service of the Centers for Disease Control (CDC). Also involved were the federal Environmental Protection Agency, the Agency for Toxic Substances and Disease Registry, the National Institute for Occupational Safety and Health, OSHA, the Tennessee Department of Health, the Tennessee Department of Agriculture, and numerous other local emergency organizations and personnel. The investigation was extremely thorough. Aerial surveillance identified potential environmental sources of contamination; personnel explored caves in the vicinity of the school; the school’s air-handling, plumbing, and structural systems were thoroughly checked; core samples were drilled from the grounds around the school; and air samples (including from the days of the outbreak) and water and waste samples were tested. The air was evaluated with an astonishing array of technology, including colorimetric tubes, flameionization detectors, photoionization detectors, radiation meters, and combustible-gas indicators.

Two years later, a New England Journal of Medicine article described the extensive examination of possible environmental causes for the illness and reported the results of the investigation by the CDC. In the end, like Rankin and Philip studying the African laughter epidemic, the investigators concluded that psychogenic factors were to blame. They found that the illness was associated with directly observing another ill person during the outbreak and with being female.¹² The diagnosis was epidemic hysteria.

This diagnosis did not sit well with the community, and it upset many of those who had been ill, such as one twelfth grader who was quoted as saying, “They said we were crazy…. It just made me mad. When I’m sick, I don’t want someone to say I’m faking. They wouldn’t have taken me to the hospital, and my blood pressure wouldn’t have been sky-high, if I wasn’t sick.”¹³ Of course, the symptoms of those with MPI. whether laughing, dancing, fainting, or nausea, are quite real; they do not “fake” their experience in the deliberate, premeditated way that a malingerer does. The astonishing reality is that our own anxiety makes us sick, but so does the anxiety of others.

The CDC investigators also discussed why communities tended to use so many resources to try to find environmental causes for conditions that appeared to be psychogenic. The problem is that while public health professionals often suspect that an outbreak is psychogenic, they feel they have no choice but to conduct an unreasonably thorough investigation because of intense anxiety in the community. And, of course, it is very difficult, if not impossible, to definitively prove that a mysterious toxic exposure has not simply escaped detection. The CDC investigators noted the possibility of a negative community reaction to an episode labeled as psychogenic, saying, “Physicians and others are understandably reluctant to announce that an outbreak of illness is psychogenic because of the shame and anger that the diagnosis tends to elicit.”¹⁴