Lucy Jones, a seismologist at the California Institute of Technology, is the author of “The Big Ones: How Natural Disasters Have Shaped Us (and What We Can Do About Them) and host of the podcast “Getting Through It.”

When the upcoming holidays inspire us to take more risks and let down our guard, we are not being resentful, stupid or selfish. We are being human. But covid-19 does not care that we perceive it to be less risky — it is more dangerous than ever.

As a seismologist who has spent much of my career helping policymakers understand seismic risk, I have seen many well-meaning and intelligent people struggle to comprehend the risk they face and weigh appropriate action. Knowing the science behind how people think about risk can help us understand why the right choices are so difficult — and why we should make them anyway.

Human beings understand reality and real-world risk using two parallel systems: an experiential, intuitive approach and an analytical, deliberative approach. The experiential system is an effective tool that has enabled human beings to survive our evolution. Long before risk analysis was a science, we relied on our gut to decide whether an animal was safe to approach or food was safe to eat.

As life became more complex, we developed an analytical system — a way to calculate and weigh risk factors rationally: assessing densities, probabilities and exposure the way engineers, scientists and economists do. But doing so takes time, work and conscious thought, so the experiential risk assessment is still a major component of our psyches and our first response to any danger.

The analytical system would tell us that the risk of catching the coronavirus is directly proportional to the number of contagious people in our community — and today, the daily case rate in the United States is skyrocketing. In many communities it is now more than 10 times what it was in April, meaning that any activity that we do now is also 10 times more dangerous than it was in April. But it doesn’t feel that way, and the psychology of how people perceive risk gives us two reasons for that.

First, we are always more afraid of things we do not understand. Early man could not protect himself from a danger he didn’t see or comprehend, so a perception of uncertainty increases our perception of risk.

In April, we did not know definitively how covid-19 was transmitted, how likely we were to die if we got it or whether it was going to be treatable. Because we know more now, the disease seems less frightening. Even though we now know that masks are the best protection, we may be less likely to wear one because we don’t feel as much at risk.

Second, our experiential system is tied to our emotions — whether something feels good or bad. We “rely on our gut” or think that something just doesn’t feel right. But these emotions mean that something we see as good, we also see as safe. Controlled studies have shown that even experts who have studied a particular risk will evaluate an exposure as safer if it has been tied to a significant emotional benefit.

Right now, after months of being in isolation, we are highly aware of the benefit of social interaction. Being with family for Thanksgiving has such a large upside that we are unable to appreciate the risk that doing so really poses. Seeing your parents now is much more likely to kill them than it would have been in April. But because it holds such benefit to both them and us, our gut just can’t agree.

Similarly, the benefits of not wearing masks — being able to see someone else’s face, the emotional benefit of that nonverbal connection with others — makes not wearing a mask seem less dangerous than it is. Notice how many public figures wear a mask but take it off to speak. The act of speaking makes your breath much more dangerous, but we discount the extra risk because of the benefits of a better social connection.

The third wave of the covid-19 pandemic is upon us just as the holidays beckon. We’re hearing a lot about pandemic fatigue, shutdown rebellions and pervasive resentment. In the same way we think that the obesity epidemic can be fixed by people just eating less, we’re blaming people for not having the character or willpower to just wear masks and self-isolate.

Instead of blaming the victims, we should try to understand why people behave the way they do. Well-meaning and intelligent people struggle to understand the hazards they face and weigh appropriate action.

But even as we recognize the difficulty, we need to use our rational minds to tell our gut to behave. Stay away from your family during the holidays so everyone will still be alive in the spring.

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