Several years ago, I was invited as a guest in a television show about hygiene in the kitchen and bathroom. I tried to make the concept of aerosol formation clear by illustrating that if you flushed the toilet, the bacteria would spread throughout the bathroom like a volcanic eruption. That's how I thought everyone would understand it.
Only a few hours after the broadcast, I received an angry email from a well-known professor emeritus.
"Don't scare people!" he hissed at me.
I was completely taken aback. I didn't want to scare people, of course, but only wanted to illustrate the concept of aerosols. In fact, studies show that after flushing without closing the toilet lid, you can even find the bacteria on your toothbrush. This is how the distribution of airborne germs works. But you don't have to be afraid of that!
How wrong I was at that time...
In the last two years, it has again become very clear how deeply rooted people's fear of the invisible is in them. But why is that the case?
In every second horror movie there is the same scene: A young, usually attractive, woman slowly creeps barefoot down the stairs. She is of course alone at home, her boyfriend or husband is away or she is a single. Some strange noise has woken her up. The cottage stands lonely and deserted in the middle of a dark forest and at least 10 miles away from the nearest neighbors. The electricity is suddenly switched off and with it the light. The spectator leans forward and holds his breath. The woman can't see anything, but her goose bumps tell us that the horror must be very close. There. The noise again. This time very close! The candle in her hand flickers briefly and goes out. Silence.
Because the invisible is what makes the hairs on the back of our necks stand up.
At this moment, the horror for the viewer is at its greatest. He stares spellbound into the television, unable to move. But the moment the murderer, the predator, the mentally ill person or the mother-in-law jumps out from behind the curtain, the fear is over. For the victim in the film, this means a flight-or-fight response, and the viewer goes along for the ride. But the breathless fear of the invisible horror is now a thing of the past.
Because the invisible is what makes the hairs on the back of our necks stand up. We don't know how to fight something if we can't see it. It scares us because we feel helpless. Flight or Fight, on the other hand, is programmed into us. If the famous saber-toothed tiger appeared then we fought it or ran away. In any case, action is called for at this moment. The end of uncertainty!
It is the same with microorganisms. We cannot see them because they are only a few micrometers in size. If we are then told that they are a terrible threat and that we are literally surrounded by them, we feel like in the horror movie. The bacteria and viruses breathe their cold breath of doom on us without us being able to defend ourselves against them. For the sake of simplicity, viruses are included among the microorganisms, although they are not living and independently reproducing organisms and are on the threshold between life and death. But the public does not make any distinction here. The size of viruses is in the nanometer range - so they are still much smaller than bacteria.
Demons invaded the population like a black foul-smelling breath and caused diseases and millions of sufferings.
Before bacteria and the role they play in the development of diseases became known, all health evils had been blamed on dark demons. Their invisible world dominated people in the Middle Ages. Demons invaded the population like a black foul-smelling breath and caused diseases and millions of sufferings. The great Christian philosopher, Saint Augustine, once said that "all the diseases of Christians can be attributed to these demons." One had a culprit and every right to defend oneself from him. The Catholic Church relied on exorcism as the means of choice to cleanse those afflicted by demons, the so-called defiled.
When Robert Koch, Louis Pasteur and other great scientists at the end of the 19th century analyzed in more detail the role of bacteria discovered by Antoni van Leeuwenhoek in the 17th century and were able to isolate them as causative agents of diseases and infections, it looked as if human race would turn away from the dark demons and enter the rational age of modern microbiology. But far from it.
The bacteria simply took over the role of the demons. The invisible threat had not changed but had only been given a new name. Yale University public health professor Charles Edward Armory Winslow wrote in the final chapter, "The Return of the Disease Demon," of his book, "The Conquest of Epidemic Disease", that belief in demons had returned, at least conceptually, to medicine in the form of bacteria.
In the early 20th century, there was a veritable panic about bacteria in the United States that differed little from the fear of demons, 100 years earlier. Drinking from a common cup or a public fountain, laundromats, books or money - everything was dangerous because, it was assumed, deadly bacteria could be transmitted with it.
They carried a white plaque on which was written in red letters "Kiss Not".
Finally, the culmination of this madness was the "Kiss Not" campaign, started in Cincinnati in 1910 by a woman named Mrs. Rechtin. Kissing is dangerous! That was the clear message. It was based on the statement of German scientists that kissing transmitted diseases. People should not kiss each other or their babies. Even the famous wedding kiss at the climax of the ceremony was to be stopped. Mrs. Rechtin had already canvassed brides for this campaign to make a statement on their wedding day.
Together with other people who followed the campaign, they carried a white plaque on which was written in red letters "Kiss Not". The members of this movement signed a common statement, "It is only in unity that sufficient strength can be gained to convince the world that kissing is pernicious and unhealthful."
In the end, the kissing ban did not prevail. The associated experience was too beautiful for people to give up this activity.
Many companies profited from the fear of bacteria. Instead of a soaked cloth handkerchief, people were supposed to buy disposable Kleenex. Advertisements showed women in a slightly raffish state with the headline "Don't be like her." The new idol was the beautiful and clinically clean woman who smelled good and additionally kept the household sparkling clean. Kellogg established itself in these years with its cereals, which were supposed to ensure adequate intestinal hygiene and protect against cancer. It was not until 2000 that a study published in "The New England Journal of Medicine" showed that cereals do not protect against colon cancer, thus putting an end to the false advertising slogan.
In recent decades, the population's relationship with bacteria has become more and more normalized. Driven by educational campaigns and great research, it became increasingly clear that it were not the pathogenic bacteria, beloved by the press for their "bad news", that were in charge. But rather the infinitely more good microorganisms that, as part of our microbiome, ensure that we can survive in this world.
But a little more than 100 years after the "Kiss Not" campaign, people's ancient fears suddenly returned.
Further reading and sources:
Healthy Fear: Bacteria and culture in America at the turn of the twentieth century; James Barlament; University of Georgia, 2002; Master of Arts thesis.