As the number of COVID-19 cases starts to rise again in many U.S. states, the question is whether residents of those states will tolerate another lockdown. I used to think so, but it is increasingly clear that Americans have become comfortable with a remarkably high number of casualties.

There is a mechanism of social conformity at work here. Most people will not tolerate a small risk to their lives to dine out, for instance — but they might if all their friends are doing the same. The appeal of a restaurant isn’t just the food, it’s the shared experience and the sense that others are doing it, too.

The danger lies in the potential for ratchet effects. If hardly anyone is eating out or going to bars, you might be able to endure the deprivation. But once others have started doing something, you will probably feel compelled to join them, even at greater risk to your life.