Today's anti-mask activists have much in common with anti-handwashing doctors of the 1840s

Inside the 174-year-history of "motivated reasoning," the psychological cause of public health pseudoscience

By Matthew Rozsa

Staff Writer

Published October 1, 2021 4:00PM (EDT)

People clap, cheer, and display protest signs during the Kentucky Freedom Rally at the capitol building on August 28, 2021 in Frankfort, Kentucky.  (Jon Cherry/Getty Images)
People clap, cheer, and display protest signs during the Kentucky Freedom Rally at the capitol building on August 28, 2021 in Frankfort, Kentucky. (Jon Cherry/Getty Images)

People were dying, and only one man knew why. He was brilliant but unpopular, and therefore fated to be rejected even though he had reason and righteousness on his side. Like so many historic geniuses, he went uncelebrated in his own time, dying in disgrace as the inmate of a lunatic asylum. Today his name is synonymous with the archetype of a brave and perceptive truth-teller surrounded by the villainously ignorant.

The story of Ignaz Semmelweis may have become a historical footnote, but it is chillingly reminiscent of the public health situation in the United States today — and in particular, the movement of millions of Americans who turn up their nose at basic public health tenets like mask-wearing. 

The man with the plan 

You may have never heard of Semmelweis, but his story likely sounds familiar. The year was 1847, and Semmelweis was a young doctor at an obstetrical clinic in Vienna General Hospital. Tasked with figuring out why maternal mortality rates were so much higher in the maternity ward run by doctors than the one led by midwifes, Semmelweis came up with a series of simple hygiene solutions. The most important rule: Require the doctors to wash their hands. He noticed that doctors would often go directly from corpse dissections into delivery rooms where they would perform medical duties. While germ theory was not widely accepted at that point as a cause for disease, Semmelweis argued that particles from the cadavers could still be "poisonous" to the mothers. Scientists believed that miasmas, or bad smells, caused disease, and Semmelweis noted that these miasmas were supposedly produced by dead bodies. His idea was for doctors to rinse their hands in a solution of calcium hypochlorite.

And it worked: Within four months, the mortality rate had dropped from above 18 percent to below 2 percent.

But fate did not reward Semmelweis for his intelligent and humane work. He was harassed and despised by his peers, professionally destroyed by office politics, ignored by the medical community and ultimately driven insane. He was eventually institutionalized and died shortly thereafter, mere years before Louis Pasteur's work on germ theory would vindicate him.

Those who opposed Semmelweis had a range of personal reasons for doing so. A large segment of the public was offended at the idea that invisible particles on their skin marked them as inherently "dirty," and that they could easily get others sick. Doctors in particular took umbrage when informed that their hands could be dirty, since they associated filth with the poor. From a religious angle, many Christians held the misogynistic belief that risking one's life should be innate to childbirth. And Semmelweis' lack of charisma may have been a problem for communicating his message: The Hungarian physician and scientist was reportedly eccentric and difficult to work with, and may have had bipolar disorder.

These motivations translated into ridiculous arguments against his conclusions. Despite Semmelweis basing his claims on observable and repeatedly demonstrable cause and effect, his ideas were dismissed as speculative. Scientists scoffed at the notion that the vast majority of childbed fevers could have been caused by a single problem like cadaver contamination, and he was similarly faulted for bucking the orthodox notion that there was more than one cause of disease. Individual errors in his thesis were nitpicked, even though its main flaw — his belief that cadaver particles were the problem and not germs in general — was one that would have even further offended Victorian sensibilities. The Semmelweis story is one in which a perfect storm of sorts came together, with the forces of cultural prejudice, scientific ignorance and petty personal dislikes aligning to all but guarantee that motivated reasoning would overpower legitimate scientific research.

It is a tragic story, to be sure, and contains an obvious lesson about how respected establishments can focus more on gatekeeping and melodrama than fulfilling their duties to the public. At the same time, there is also a romance to the archetype that Semmelweis represents. It feels good to believe that you are smarter than the people widely perceived to be intelligent, or more moral than those entrusted to lead society. That desire for a positive self-image causes many people to behave stubbornly when confronted with evidence that their views are wrong. In their minds, they play the role of Semmelweis, and everyone shoving evidence in their face is an ignorant Viennese doctor circa 1847.

But the most curious (and apropos) aspect of the Semmelweis saga may be the way in which his detractors fought him despite his quantitative evidence. The number of deaths were lower when doctors washed their hands. Shouldn't that be enough? 

Something psychological was happening, something that Semmelweis couldn't account for. It involves a human trait that psychologists call motivated reasoning. And it couldn't be more relevant to the pandemic today. 

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Motivated reasoning and you

While the scientific literature supporting masks is straightforward and indisputable, how they work should be self-evident. The essence of science is empiricism, or the understanding that knowledge is acquired from what we can perceive using our senses. If you cough, talk, exhale or otherwise expel droplets from your mouth and nose, most if not all of those droplets will be contained by any physical barrier placed over those orifices. Since this virus is transmitted through those bodily fluids, it is logical to say that wearing masks will help limit the spread; some materials are more effective than others, and there is always more research to be done on mask efficacy in specific contexts, but the bottom line is clear.

A similar principle applied to the problem of hand washing in 1847. Germ theory had not yet been commonly accepted, but anyone who understands how touch works knows that if you put your hands on something potentially unhealthy, you might transmit the dangerous particles to another person. Since there is no more harm in washing one's hands than in wearing a light mask over one's face, it might seem nonsensical (by today's standards) that one might argue against such a mild precautionary measure when the literal life-and-death stakes were so high.

The problem was, in that particular case of motivated reasoning, the demands of the motives cancelled out the requirements of reasoning.

Motivated reasoning is, quite simply, when a person's emotions incentivize them to produce justifications for a position that they desire to hold rather than the one which is actually supported by evidence. It is closely related to confirmation bias, which is when people embrace ideas and "evidence" that confirms what they want to believe and give less weight to facts which do not. While a person practicing motivated reasoning could also be correct about a given issue, that will usually be a coincidence. When a person holds a view due to motivated reasoning, they are driven by their emotions, not by their reason — no matter how vehemently they insist otherwise.

So it is with the motivated reasoning of the facemask opponents. Just as conservative political assumptions helped motivate the anti-hand washers of Semmelweis' day, a May study found that conservatives are much more likely to have inaccurate knowledge about mask-wearing efficacy and other coronavirus-related subjects than liberals. 

As right-wing leaders like President Donald Trump and media outlets like OANN downplayed the importance of wearing masks, and local officials opposed or flouted masking regulations, Americans who opposed liberal politics learned to associate not wearing masks with taking a stand against the left. This has led to erroneous anti-mask arguments that vary from exaggerating supposedly disqualifying health issues, to wrongly claiming there is no scientific consensus on the matter, to claiming mask mandates violate one's freedom. Some mask opponents insist facemasks form part of a government conspiracy.

Motivated reasoning not only affects the end results of our beliefs, but it affects how we formulate them, too. 

"When we're engaging motivated reasoning, we tend to hold evidence to a lower threshold of quality before we believe it's true," Dr. Nicholas Epley, a professor of behavioral science at the University of Chicago, told Salon by email. "A person trying to justify a belief they have might ask themselves 'can I' believe this to be true, while a person trying to refute a belief they'd rather not have holds evidence to a higher standard, asking themselves 'must I' believe this to be true.  Both are motivated approaches to evaluating evidence. The first can lead us to accept weak evidence in support of a belief, while the latter can lead us to be overly skeptical of good evidence."

He added that the underlying problem — to mask opponents, or any motivated reasoning-spurred argument — is that one might start with a conclusion that one wishes to reach (e.g. "face masks are wrong"), then retroactively construct arguments to justify it.

"If you start with the conclusion that masking is wrong, then the motivated reasoning becomes an attempt to identify the harm that it causes," Epley noted.

This is evident in many of the specific claims made by mask opponents. 

"The turning to irrational thought to defend inaccurate beliefs is evident in the quotations 'masks do not prevent the spread of the coronavirus,' 'masks are bad for children,' 'young people are not at risk,'" said Dr. David Reiss, a psychiatrist and expert in mental fitness evaluations. Reiss culled these quotes from a recent anti-mask rally held by Steve Lynch, the Republican candidate for county executive in Northampton, Pennsylvania, who infamously called for 20 "strong men" to remove school boards that pass mask mandates.

Reiss had a similar observation about those who attack masks using religious language, describing it as "grandiose thinking, in essence 'I have access to a level of knowledge that supersedes and replaces logic.'" When one anti-mask protester read from the Book of Psalms, it was an irrational distraction because "whatever one might believe regarding the Book of Psalms, the Book says nothing about the science of epidemiology and prevention of disease."

Motivated reasoning is something everyone does

If there is anything to be learned from mask opponents, it is that we should be mindful of the signs when we allow motivated reasoning to cloud our judgment. After all, every human being has motives, and all of us inform our world view based on those motives. The goal is not to eliminate motivated reasoning, which is inherent to our nature, but to make sure that it does not cloud our judgment.

"Start by asking what the evidence is before deciding what the conclusion is, and then genuinely look at the evidence before arriving at a conclusion," Epley told Salon when asked how people can avoid lapses in judgment due to motivated reasoning. "This is much easier advice to give than to actually follow in practice."

It is telling that nearly two centuries after the Semmelweis tragedy, so many people have failed to follow the scientific methods to which he devoted his life. Semmelweis was literally driven to ruin because he wanted to use science to protect public health. If nothing else, he earned the right to be deemed a champion for truth.

By Matthew Rozsa

Matthew Rozsa is a staff writer at Salon. He received a Master's Degree in History from Rutgers-Newark in 2012 and was awarded a science journalism fellowship from the Metcalf Institute in 2022.

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