In a public Facebook thread of comments we followed recently, people were posting their reactions to a news story about the development of a COVID-19 vaccine. It had just been announced that 200,000 Americans had died from the novel coronavirus since the pandemic began, but commentators seem to want to put that number in perspective. One brought up the number of people who die from cancer every year in the U.S.—about 600,000—and another the staggering global mortality rates from starvation—around 9 million.
Were they trying to say that the number of COVID-19 deaths is so small in comparison that we should somehow not be concerned? While we cannot dispute that 200,000 is a smaller number than 600,000 or 9 million, that comparison does not seem reasonable to us. The loss of 200,000 lives is tragic. We should pay a lot of attention to these other causes of death (in the case of cancer we actually do), but that doesn’t mean we should discount the loss of lives to a newly emergent pathogen that could be mitigated if people wore face masks while in public all the time and practiced social distancing. A vaccine will hopefully bring an end to the pandemic at last.
It does seem that people have trouble feeling the impact of large numbers. An article by Sarah Elizabeth Richards at the end of September in National Geographic nicely laid out the problem. In “Why our minds can’t make sense of COVID-19’s enormous death toll,” Richards writes, “Researchers say our brains aren’t wired to make sense of big numbers.” A story about a single tragic death evokes waves of sadness and emotion in us. We focus on the individual’s details, their life story, and the circumstances of their death. As the number of victims increases, our ability to muster empathy fades, something often called compassion fatigue.
For example, consider a hypothetical example of a 28-year-old woman who has just died from cervical cancer. We will give her a name, Constance Johnson. Imagine that she was a nurse who worked long hours in a hospital intensive care unit taking care of very sick patients. Her superiors, colleagues, and patients all gave her the highest ratings. She was engaged to be married when the diagnosis of cervical cancer was first made and despite aggressive treatment, she died. This kind of story has been used to encourage people to have their sons and daughters receive the vaccine against the human papillomavirus (HPV), the virus that can cause cervical cancer. Constance wasn’t vaccinated, so it is very possible her death was preventable. Campaigns like this appear to be effective because they strike an empathic and compassionate chord within us; we can relate easily to the tragedy and feel the anguish of her family.
If we talk instead about multiple people like Constance Johnson at once or just give the numbers involved—about 4,200 women die every year from cervical cancer—the information loses its impact. We don’t comprehend a number like 4,200 the way we do the story of a single individual.
Compassion Diminishes Rapidly
As the results of a study by Paul Slovic and colleagues in 2014 showed, the tendency to be charitable and feel compassion diminishes rapidly as the number of people involved increases from one. The researchers write that “The results from four studies show that affective feelings about charitable causes were strongest for a single endangered person and began to decline as the number in danger grew larger. In support of compassion fatigue, both self-report and physiological measures of affect showed that positive affect declined substantially when the group size was two or more.”
What exactly is going on in the brain that accounts for this problem of compassion fatigue when the number of affected people becomes larger? As Richards notes, “Our neurons fire when something changes, but they stop after a while.” Indeed, our brains operate by the passing of signals from one brain cell, or neuron, to the next. There is a gap, or synapse, between two neurons that must be traversed by a chemical neurotransmitter. As an electrical signal reaches the end of one neuron, the presynaptic neuron, it triggers the release of one of the many varieties of neurotransmitters into the synapse and it then binds to a receptor on the next, or postsynaptic, neuron. If the neurotransmitter is an excitatory one like glutamate, it opens a channel and causes a series of events that propagates the electrical signal so that it continues moving down the postsynaptic neuron.
After several puffs of neurotransmitter are released, however, that channel may undergo a process called “desensitization” in which it closes and stops responding to signals from the presynaptic neuron. The electrical signal is thus blocked. We’ve actually described this process very simply (like everything else in the brain, the details become increasingly complicated), but it is one good way of understanding the physical process Richards is alluding to. Neurons respond to the story of Constance Johnson, but if we start increasing the number of affected individuals they desensitize to the stimulus so that we no longer feel its full impact.
The Medial Prefrontal Cortex and Large Numbers
We even know something about where in the brain all this is happening. In a 2020 study in the journal Scientific Reports, scientists (including Paul Slovic) first noted that there is a “core network of human empathy, composed of the medial prefrontal cortex (mPFC), middle cingulate cortex, and bilateral anterior insula. In particular, the mPFC and middle cingulate cortex have been linked with cognitive empathy and the right anterior insula with affective empathy.” Cognitive empathy is the thoughts we have about someone else’s situation and emotional empathy is how we feel about it.
In the study, titled “Brain imaging evidence for why we are numbed by numbers,” the researchers used the brain imaging technique functional magnetic resonance imaging (fMRI) to show that the mPFC was activated more by events involving a single person than it is by events involving multiple people. They concluded, “Observing that the tendency to mentalize with one person more than many people is built into our brains does not mean we should accept it as an excuse for acting passively when facing large-scale crises. This observation implies, however, that we can no longer rely on our moral intuitions.”
What the authors suggest is that we have to deliberately override the tendency to dismiss tragedies involving lots of people in order to act like moral people.
Most people do not know someone who has died from COVID-19 and therefore do not have stories immediately at hand that bring home the suffering the disease causes. Media sources usually refrain from showing us pictures and videos of people struggling to breathe or lying alone in ICU beds on respirators. And we don’t always get individual stories or images of the dead. Because of this, people may cope with the enormity of the pandemic by trying to find ways to minimize or even dismiss it. Saying that there are other diseases that cause more deaths than COVID-19 could be one such emotional mechanism.
We need to tell more stories about real people who have had COVID-19 and experienced it as more than mild symptoms, including stories about people who have been killed by the disease. The stories need to be told one by one. That way, we will be harnessing what we know from cognitive neuroscience to bring the sad message home.