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    The science and psychology behind masking to prevent the spread of COVID-19

    Experts weigh in on the most effective mask-wearing practices, the psychology behind not masking, and how to communicate its importance.

    Amy Price, DPhil, a senior research scientist at Stanford Anesthesia Informatics and Media Lab, wears a cloth mask like the ones she and her colleagues tested for efficacy of containing viral particles.
    Amy Price, DPhil, a senior research scientist at Stanford Anesthesia Informatics and Media Lab, wears a cloth mask like the ones she and her colleagues tested for efficacy of containing viral particles.
    Courtesy: Amy Price, DPhil

    As COVID-19 infections continue to climb across the United States, scientists, physicians, and public officials are calling on people to wear face masks to help stop the spread of the virus.

    Mounting scientific research shows that widespread wearing of masks, along with practicing social distancing and frequent hand-washing, would greatly reduce community transmission of the virus. The effectiveness of masking was recently highlighted by a study that found two COVID-19-positive Missouri hair stylists did not pass the virus on to any of their 139 clients. The stylists and their clients wore masks.

    Still, many Americans are not complying with public health guidelines or are using masks that may not effectively block infected droplets.

    Psychology can play a role in adherence to public health guidelines — whether people defy mask mandates as violations of their freedom or relax masking measures when they don’t feel threatened.

    The disconnect between the guidance and the practice is further exacerbated by conflicting messaging and misinformation around masking.

    AAMCNews asked four experts about different aspects of masking that can help inform the medical community and make them more prepared to set a good example and communicate effectively with their patients, peers, and loved ones about masks.

    How to make and use masks effectively

    Amy Price, DPhil, a senior research scientist at the Stanford Anesthesia Informatics and Media Lab, and Larry Chu, MD, a professor of anesthesia and the laboratory’s director, studied how to make cloth masks most effective and advised the World Health Organization (WHO) on its latest guidelines.

    How do masks work?

    Wearing a cloth mask can trap droplets that come from a person’s mouth when they cough or sneeze, Chu says. If a person is infected, including someone who is showing no symptoms of the disease, those droplets can spread the virus to other people. Trapping the large droplets that travel through the air, as well as the small particles that form an aerosol and linger in enclosed spaces for up to 30 hours, is called “source control.” It prevents the infected droplets from reaching other people.

    NPR reported last week that a team of researchers from the University of Washington’s Institute for Health Metrics and Evaluation estimated that if 95% of people wore a cloth mask in public, it could reduce transmission by 30%.

    Do they protect the wearer?

    A mask likely does not directly prevent the wearer from contracting the virus because any gaps between the mask and the person’s face leave room for virus particles to seep through, Price explains.

    But there is still debate on the matter. A new paper by three physicians from the University of California, San Francisco, School of Medicine and Johns Hopkins Bloomberg School of Public Health that is set to be published in the Journal of General Internal Medicine next month hypothesizes that wearing a mask may reduce the amount of virus that infects the wearer, potentially lessening symptoms.

    Wear a cloth mask with three layers

    Price and Chu say that their research shows masks are most effective at keeping the wearer from infecting others when they have a water-resistant outer layer, such as cotton mixed with polyester, nylon, or rayon; an inner layer of polypropylene or two layers of facial tissue, which can be replaced after each use; and an absorbent inner layer, such as 100% cotton.

    A good way to determine if a mask is thick enough is to hold it up to the light. If you can see gaps in the fabric, it’s too loose, Price says. A bandana, for example, is generally too thin and loosely woven to provide much protection, according to their research.

    Chu also says consumers should be skeptical of claims that masks made with zinc or copper could have antiviral properties.

    The WHO recommends that single-use medical masks be reserved for and worn by health care workers, people who have COVID-19 symptoms, those caring for people with confirmed or suspected COVID-19, and people over the age of 60 or with underlying health conditions.

    Electrical charge can add a layer of protection

    Price recommends adding an electrical charge to a cloth mask by rubbing it with plastic or a rubber glove for about 30 seconds. The static electricity can last all day and adds an additional barrier for the virus to get through, she says.

    Wash your mask every day

    Price says that you should treat your mask as if it has biohazardous waste on it. Avoid touching the mask and remove it only by the ear straps. When not using it, place it in a sealable bag. The WHO recommends washing the mask with hot water and soap after wearing. Stay safe by treating your mask like your toothbrush and not sharing it with anyone.

    She also warned that N95 respirator masks and other medical masks are only good for one use unless they are decontaminated.

    When to wear a mask

    Experts are still studying how and where the virus is most likely to spread, but many believe that transmission of the virus is less likely in outdoor areas where open air and wind can dilute the viral particles, the New York Times reported in May.

    The Centers for Disease Control and Prevention recommends that the general public wear masks whenever they are in a public setting and around people who do not live in their household, especially when a distance of six feet is difficult to maintain.

    Wearing a mask isn’t unhealthy

    Price and Chu were quick to debunk popular misinformation that has circulated claiming that masks cause the wearer to inhale higher amounts of virus and that wearing a mask can have negative health impacts on the wearer.

    “I’m an anesthesiologist. I wear a face mask every day for work. I have for my entire career, so have hundreds of thousands of doctors and dentists,” Chu says. “Certainly, we don’t see an epidemic of people suffering from bacterial or fungal pneumonias, or lack of oxygen, or carbon dioxide retention. There just isn’t evidence to show that that’s the case from wearing face masks.”

    The psychology behind adherence to mask policies

    David Abrams, PhD, is a professor of social and behavioral sciences at the School of Global Public Health at New York University and former director of the Office of Behavioral and Social Sciences Research at the National Institutes of Health. His major interest is in using the science of behavior change to improve population health.

    “Fight or flight” when under threat

    While scientific evidence makes it seem like wearing a mask is a simple way to help fight the COVID-19 pandemic and protect fellow humans, many people do not think rationally when faced with the threat of an unknown, Abrams explains.

    “Your brain gets into what we call a hypervigilant adrenal situation,” he says. “It feels like the rug is being pulled out from under you. To be prepared for a rapid reaction, we see hot emotions overriding cool rationality … You fall back on survival instincts, which could be, ‘I’m going to posture for a fight and be defiant. I’m in control,’ when, in fact, you’re out of control.”

    When emotions are high, many also exhibit “confirmation bias,” which is when people only look for and accept information that supports what they’ve already decided is the truth.

    “It heightens the tribal nature and the political divide,” Abrams says. “They bond with the tribe either wearing or not wearing masks and dig their heels in to defend their position.”

    Letting one’s guard down

    But it’s not only those who actively denounce masks who can be seen not following the guidelines. Some people may let the mask rest below their nose or on their chin while out in public. Others take the mask off when talking to others.

    This happens because human nature is not good at judging probability in the moment, Abrams explains. They may let their guard down and take off their masks if they feel safe or rationalize that since they have been OK for months, it’s not so bad to take off the mask for a little while.

    Abrams observes that younger and healthier people tend to downplay the risk of the virus to themselves. He says it is similar to what he’s observed with addictive behavior programs where people who are smoking cigarettes or driving while intoxicated rationalize their behavior.

    On top of these factors, humans rely on nonverbal communication — and particularly facial expressions — to read and connect with each other, Abrams says.

    “So, there’s an inclination not to want to cover your face or to want to see the other person’s face,” he says. “Seeing and observing facial expressions is important to us.”

    Making the mask plea with empathy

    As many people in the country continue to either ignore or flout masking protocol, some who support wearing masks — and particularly those who are studying medicine or working in the medical field — may find themselves urging their patients, friends, family members, and others to follow the guidelines. Abrams says that the way this message is communicated matters.

    “Be respectful and avoid being judgmental. Use that understanding to have an open conversation,” Abrams says. “I think it’s the same thing that applies to how we suggest students and medical professionals talk with their patients. One of the most important things is to be empathic and acknowledge their perspective.”

    A potentially effective way to persuade someone could be to make the threat personal by asking how they might feel if a loved one contracted the virus and became very ill or even died.

    But it’s also important to remember to set your own limits, Abrams says.

    “If you’re getting nowhere, you may say, ‘I feel uncomfortable being close to someone who doesn’t want to wear a mask. Please excuse me, but I am going to have to distance myself,’” Abrams recommends.

    “Be respectful and avoid being judgmental. Use that understanding to have an open conversation. I think it’s the same thing that applies to how we suggest students and medical professionals talk with their patients. One of the most important things is to be empathic and acknowledge their perspective.”

    David Abrams, PhD
    Professor of social and behavioral sciences at the School of Global Public Health at New York University

    How to turn the tide

    One major complication in getting the American public to embrace wearing face coverings has been a lack of consistency in messaging, according to Linda Aldoory, PhD, a professor in the Department of Communication and associate dean of research and programming at the University of Maryland.

    “In this crisis, what’s unprecedented is the conflict between two national sources: the public health agencies and political sources,” she says. “You usually see a little confusion, but there’s generally a unifying message at the national level.”

    With public health messaging, the strategy usually involves presenting the facts, appealing to the public’s values, and then providing a solution.

    “With masks, it’s a battle of values,” Aldoory says. “Here we have the values of public health versus the values of personal freedom.”

    But aligning the credible sources to communicate a unified message could go a long way, she says.

    Abrams agrees.

    “It’s crucial that all leaders and role models be seen to consistently wear masks,” he says. “Actions speak louder than words. Even then, it takes a little time for a whole nation to adapt to a new norm and have it diffuse through a culture.”