World War C

by Sanjay Gupta

  Your Own Risk Tolerance

  In February 2020, my friend and colleague Jake Tapper called me one day to talk about a possible trip he was considering for his family over their upcoming spring break. One of his children has asthma, and so they asked their pediatrician about the risks. At the time, there were around a dozen new confirmed cases of COVID in the country, and he relayed to me that the doctor had told them there was “probably around a 0.1 percent chance of his son having a significant problem.” Before I could respond, Jake then said, “So, of course, we decided to cancel the trip.” As a doctor myself, my guess was the pediatrician was probably trying to allay his anxiety by citing such a small number, but for the Tapper family, it represented enough of a risk to pull back on their travel plans. Spending time on a beach wasn’t worth the one in a thousand chance something could go dramatically wrong.

  On another occasion, I was in the middle of a series of Zoom calls with school administrators during summer 2020. I was working on a story about school reopenings and trying to get a better idea of the plans they were putting in place. At one point, I cited some early data coming out of Wuhan suggesting that the virus had a case fatality rate of around 0.5 percent. There was a long pause, and then a superintendent said, “Whoa… 0.5 percent. That means 1 in 200 people will die? That is really concerning. We need to really take care and protect ourselves.” Later on that same day, another person responded to the same data: “So, 0.5 percent. I guess that means we are 99.5 percent good, then, right?” A completely different response. (I mentioned these percentages much earlier in the book but now let’s tease this further apart within the context of how people can make such divergent interpretations.)

  It was an illuminating series of discussions that reminded me that while people may hear the same objective data, they interpret those data very differently. For many people who were able to stay home through the pandemic, even a small risk was too much. For frontline and essential workers, who had no choice but to show up, the risk tolerance could be much higher. We saw that play out in different ways throughout the pandemic in the United States. And as we started to evaluate risk tolerance across cultures, the differences became even more pronounced.

  What We Value

  I once did a story about an international group of researchers who came together from the University of British Columbia, MIT’s Media Lab, Harvard University, and the Toulouse School of Economics in France to evaluate the concept of risk from an intriguing perspective: teaching the artificial intelligence of self-driving cars how to make a split-second decision when there is no way to avoid a fatality.2 How would a car determine which person or group of people should be “sacrificed”? Science fiction fans will immediately recognize Asimov’s law: A robot cannot kill or harm a human through action or inaction. But what if there’s no choice? What if the brakes fail, and there is no scenario where the autonomous vehicle can save everyone?

  If it sounds familiar, it’s because it is a version of the classic ethical thought experiment known as the trolley problem: Five people are tied to a trolley track with a car bearing down on them. You can throw a switch redirecting the car to another track to which only one person is tied. What do you do: Take responsibility for the death of one person or allow five others to die by doing nothing? In a further iteration of the problem, the five people can be saved only if you physically push a fat man onto the track to stop the car with his body.

  The more recent study, dubbed the Moral Machine experiment, launched in 2016 and allowed more than 2 million people around the world to play a game that showed preferences for sparing or, conversely, sacrificing different types of lives. It generated nearly 40 million decisions in ten languages, becoming the largest crowdsourced ethical study worldwide. People who played the Moral Machine game were shown two images, each depicting an out-of-control car driving into a different group of people (or, in some of the images, a cat or a dog). For example, the game might tell you that if you let the car plow ahead, it will kill three little girls and two adult men. But if you swerve to the right, the car will instead kill two elderly men, two elderly women, and a young woman. Which way to swerve? Who would you kill? I found myself playing it at the kitchen counter one day, and soon my entire family was running the sacrifice scenarios.

  Morbid indeed, but also revealing. The most likely to be saved were babies, children, and pregnant women. That wasn’t surprising. Athletes and businesspeople were often saved at the expense of homeless people and overweight men. Doctors scored just below nurses. It turns out cats were most likely to be sacrificed. And here is where this thought experiment became so relevant to this pandemic: the sacrifice of the elderly. The data showed that in the hierarchy of sacrifice, old people came just behind cats and criminals! That all humans should be spared before pets seems morally correct but in this experiment, dogs were saved more often than criminals (and criminals won over cats). Almost always, the car was taught to swerve toward someone who was old, just like COVID did. Remember that early on in the pandemic, we quickly learned the disease was disproportionately killing the elderly, as we saw extended care facilities account for a third of all deaths in the United States.

  It really got me thinking: What if the COVID pandemic had primarily killed young people instead of older folks? Would we have responded differently in the United States? Would our risk tolerance as a country have been lower? On the flip side, did the cultural reverence for the elderly in Asia lead to a more aggressive response there? Although a preference for sacrificing the old to save the young was found in every country during the Moral Machine experiment, the places where people showed the weakest preference for killing the old were in East Asian countries, places that also had some of the lowest death rates overall in the world.

  The study unveiled a bitter truth that many of us knew in the back of our minds, even if we are reluctant to admit it: Certain deaths bother us more than others do—and what bothers you might not bother your neighbor. This is the reason to develop a risk assessment as a society that takes into account these subconscious prejudices and works to neutralize them.

  And that is not the only obstacle to coming up with a rational response to a pandemic like this one. Our brain, the ultimate risk assessment tool, was at an incredible disadvantage initially because it had no previous memory of this particular threat.

  Your Brain: Playing the Odds of What We Remember

  When many infectious disease doctors first heard of a coronavirus from China, it immediately triggered a memory in their brain: SARS. They therefore reflexively put this new virus into a “SARS box” in their brain, anticipating the virus would spread only symptomatically and just disappear over time. That presumption ended up being a terrible mistake, putting many people in harm’s way until we understood how COVID behaved.

  The problem is a fundamental one in the world of neuroscience. The adult brain is not very good at accepting truly novel experiences. A fully mature brain will always scramble to fit the new experience into an existing one. Kids, in contrast, are wonderful at dealing with novel experiences because early in life, everything is new. That ability diminishes as we get older. We adults become increasingly reluctant to accept that something is truly novel, confident instead that we have seen it all before. After all, I’ll ask again: When is the last time you experienced something for the first time?

  Such a phenomenon—the inability to process a new experience—is something Daphna Shohamy, professor of psychology at Columbia University’s Zuckerman Mind Brain Behavior Institute, has been studying for some time. She recently collaborated on a study that looked at how patients with damage to the hippocampus, the memory center of the brain, made decisions.3 The research team asked these patients to make a series of very simple decisions like choosing between Kit Kats and M&Ms or between pretzels and potato chips—the sorts of mindless decisions we make all day long. Without fail, however, the group of people with damage to the hippocampus took two to three times as long to make th
ese decisions as compared to those with intact memory.

  According to Shohamy, this kept happening for a specific reason. Despite having no memory of these particular foods—how they tasted, whether they were satiating—their brains struggled to come up with any evidence whatsoever that would help them make that decision. It was like the brain was in a constant loop, looking to find a single morsel of data to help guide the decision.

  “Eventually, in those cases, the brain basically just makes a prediction,” Shohamy tells me. While it is the most educated guess it can make, many times the brain gets it wrong. The lesson is a profound one when assessing your own risk. Trying to recall evidence or memories that don’t exist will just get in the way, slow you down, and quite likely end up being incorrect. Instead, it takes clearing the mind and not letting preconceived notions hinder you that can more accurately help you evaluate the risk.

  With COVID entrenched in our environment, we will now have to regularly evaluate risk and make decisions that affect not just ourselves but everyone around us—loved ones and strangers alike. Although we’ve been making decisions all our lives that affect others, the pandemic adds a new complication that each individual must consider like never before. The virus may mutate down a notch or two to become less virulent and deadly, but its presence will nevertheless probably be perpetual. As technology improves and we continually learn more, we will likely see improvements to indoor ventilation systems and protective measures that could make indoor spaces safer overall, but the risk will never be zero. And we may never reach that elusive herd immunity in the United States or worldwide no matter how much we try to vaccinate. The combination of vaccine hesitancy and a small percentage of people who don’t respond strongly to the vaccines has compromised our ability to get there. And those who are not vaccinated for whatever reason can fuel breakthrough cases and more variants. The world will remain a patchwork quilt of populations relatively safe from the virus and populations that will experience outbreaks. We must learn to live with this virus for the rest of our lives and factor its risk into our days, a mental process that should become relatively automated just like a self-driving car that needs to make navigational decisions to prevent accidents. The first step to getting there is better understanding your brain.

  Rewire Your Brain

  I’m spoiled in my brain world. I get to work with an organ that continually changes and reshapes itself—perhaps the only organ in the body that can grow better with age. Every time you experience something new (like the pandemic), your brain slightly rewires to accommodate that new experience. Novel experiences and learning cause new dendrites to form, which are segments of brain cells that receive electrical impulses (dendrite literally means “treelike” because they are short-branched extensions of a nerve cell that reach out to nearby brain cells). With repeated behavior and learning, your existing dendrites become more entrenched. Both the formation of new dendrites and the reinforcement of preexisting ones are important, of course. The creation of new dendrites, even weak ones, is called plasticity. And it is this plasticity that can help your brain rewire itself if it is ever damaged. It is also the core ingredient for resilience, vital for building a better brain.

  So as you navigate the postpandemic world and learn new things, changes happen to the synapses and dendrites: more connections are generated, while others may be weakened. The brain constantly organizes and reorganizes itself in response to your experiences, your education, the challenges you face, and the memories you make. These neural changes are reinforced with use and memory (hence the saying “What wires together fires together”).

  We all experienced some serious rewiring at various times throughout the pandemic as we normalized certain new behaviors like wearing a mask, keeping physically distant from others, and washing our hands a lot more frequently. For some, the rewiring made it harder to shift our habits again when COVID restrictions eased and we were told we could be maskless under many circumstances. My teenage girls, for example, adapted very quickly to wearing masks; it became second nature to them. Even as masks became increasingly unnecessary with vaccination, they still slipped the ear loops on as they walked out the door. Their younger brains encoded this new behavior more easily and more forcefully than their parents’ older brains. And the ease with which our brains can perform this electrical mental “redecorating” makes us uniquely adaptable. It’s just like learning to play a musical piece. If you play Beethoven’s Moonlight Sonata on the piano over and over, for example, the repeated firing of certain brain cells in a certain order makes it easier to replicate this firing later. The result is that you get more adept at playing the piece effortlessly. If you stop practicing for several weeks, though, and then try to play the piece again, you may not be able to play it as skillfully as before. Your brain has already begun to “forget” what you once knew so well. The dendrites that were so clearly defined start to wither away a bit fairly quickly. Luckily, it is not difficult to read the notes even years later and build up those neural connections once again.

  Similarly, we may need to mask up again in future years, for which the wiring we’ve established in the COVID era will come to good use. We now have that all-important memory to motivate us and switch into COVID control mode quickly. The pandemic-proofing habits we want to put into place going forward will require their own wiring, but the beauty of our brains is that they make it all possible. As much as you initially resisted public health measures to combat the pandemic, you eventually got used to it. And while you might resist new lifestyle habits in your personal prep for another pandemic, my guess is you’ll soon get used to that too. Your brain, and your peace of mind, will thank you.

  The Risk Spectrum in Everyday Life

  The Infectious Diseases Society of America helps determine which activities can be categorized as low, medium, and high risk when there’s a pathogen to factor into daily life.4 Of course, how that pathogen behaves and is transmitted matters. With COVID, a very tiny percentage of cases happen from viral transmission outdoors, regardless of vaccination status, making activities outside much lower in risk; the odds of transmission indoors, however, are more than eighteen times greater. Six feet may never be enough for indoor settings to be safe when it comes to COVID. A group of researchers at MIT found that the risk of being exposed to COVID indoors is as great at sixty feet as it is at six feet—even when wearing a mask.5 This group, led by engineers and mathematicians, developed a method of calculating exposure risk to COVID in an indoor setting that factors in a variety of issues that could affect transmission, including the amount of time spent inside, air filtration and circulation, immunization, variant strains, mask use, and even respiratory activity such as breathing, eating, speaking, or singing. The fact that aerosolized virus particles can travel far and stay in the air for prolonged periods makes indoor settings all the more problematic no matter how far you are from other people. Think of it like cigarette smoke. Even if someone is smoking in a room on the other side of the house, you will eventually smell it. The lesson: outdoors trumps indoors. For future pandemics, a critical question will be whether the pathogen spreads primarily via aerosol or respiratory droplets.

  As COVID vaccination status for the country increases overall, the risk threat will decrease in all categories. If you have been vaccinated for COVID, your risk of becoming seriously ill is very low. We now know your risk of becoming infected is also low as is the likelihood you will spread the virus if you do develop a breakthrough infection. The risk primarily is for unvaccinated people to spread the virus to other unvaccinated people. As Barney Graham, deputy director of the NIH vaccine research center told me, the country won’t split into vaccinated and unvaccinated. Given the contagiousness of the virus, with time, the country bifurcates into vaccinated and infected unless basic public health precautions remain in place for those who aren’t protected. What the science teaches us at this time is highly transmissible variants may mean masking up even if fully vaccinated.

&n
bsp; It’s All Relative

  The real question we all have to ask ourselves is this: What’s the chance something will happen to me? You can have low-, medium-, and high-risk labels on various activities but still be stuck trying to figure out how they apply to you and your personal risk profile. Spending time with someone outside your household may seem low risk, but that may not be the case if that person carries the virus unknowingly and you have underlying conditions associated with worse outcomes. Risk is personal.

  I have to deal with relative risk with my patients daily. In the simplest terms, risk is the chance something will happen. Relative risk of something happening is calculated when you compare the odds for two groups against each other. For example, the relative risk of developing lung cancer in smokers versus nonsmokers would be the probability of developing lung cancer for smokers divided by the probability of developing lung cancer for nonsmokers. If we hypothetically find that 17 percent of smokers develop lung cancer and 1 percent of nonsmokers develop lung cancer, then we can calculate the relative risk of lung cancer in smokers versus nonsmokers as:

  Relative risk = 17% / 1% = 17.

  Thus, smokers are seventeen times more likely to develop lung cancer than nonsmokers.

  An important point to remember is that the relative risk does not provide any information about the absolute risk of the event occurring, but rather the higher or lower likelihood of the event in the exposure versus the nonexposure group. Absolute risk is the odds of something happening over a particular period of time. For example, according to the National Cancer Institute, a woman living in the United States has an absolute risk of 12.4 percent of developing breast cancer in her lifetime. That means for every 100 women, around 12 will develop breast cancer at some point in their lives.