Who's Afraid of Friday the Thirteenth? Good Luck with That

Eeek! It’s Friday the 13th , the unluckiest day of the year.

Every year has at least one of these days, and some have as many three.

According to one estimate, some 20 million Americans fear Friday the 13th , which means that some 20 million Americans believe in utter bullshit.

There’s no scientific basis for thinking that a Friday which falls on the 13th day of a month is more dangerous than any other. Moreover, no one’s quite sure when or where this idea came from.

But that doesn’t stop throngs of people from believing it, and these beliefs have consequences.

This superstition will disrupt between $700 and $800 million worth of business that would otherwise have taken placed today.

Many people rearranged travel plans. Others are “working from home” to stay off the roads. Some won’t even get out of bed.

If there’s a net upside to their unfounded fear, it’s hiding—like one of Jason’s victims the classic horror movie named after this day. Society would almost certainly be better off without its false belief in Friday the 13th .

But let’s not throw out the superstition baby with the Friday the 13th bathwater! Some superstitions, believe it or not, actually make society better off. Widely-believed bullshit can be beneficial, which explains why some of it emerges in the first place.

Consider polygraph tests. There’s about as much scientific evidence supporting the idea that lie detectors can physiologically detect lies as there is supporting the idea that Friday the 13th is unlucky. Yet, like belief in the latter, belief in the former is widespread. And it’s a good thing; for, our criminal justice system works better as a result.

Imagine you’ve been hauled into a police station under suspicion of having committed some crime. You, of course, know whether you’re guilty or innocent, but your interrogators don’t. If they just ask you about your guilt, you’ll probably say you’re innocent even if you’re not.

So your interrogators try something else: ask if you’re willing to take a polygraph test. Like many other Americans, you (falsely) believe that polygraph tests can physiologically determine if you’re lying or telling the truth. Will you take the test?

First, suppose you committed the crime: In this case, you expect that if you take the polygraph, you’ll be outed as guilty. Better to decline the test, maybe even to fess up; by coming clean, you might manage to get a better plea deal.

Now suppose you didn’t commit the crime: In this case, you expect that if you take the polygraph, you’ll be exonerated. Better to take the test than confess to a crime you didn’t commit.

In other words, if you’re guilty, you’re more likely to confess when faced with this simple choice. And if you’re innocent, you’re more likely to take the test.

Given your false belief about polygraph tests, by simply offering you the option, your interrogators learn important information about your probable guilt or innocence! And with better information about your actual criminal status, justice has a better chance of being served.

Note that the heavy lifting here is done by your superstition, not the polygraph. Indeed, the polygraph “works” only because of your superstition. If you believed that they were bogus, lie detectors would be as worthless for separating the innocent from the guilty in practice as they are for doing so as a matter of science.

Socially productive superstitions aren’t limited to false beliefs about lie detectors that improve criminal justice. They litter our world—past and present, from America to Liberia—and help us in everything from protecting our property to resolving our conflicts to enforcing our contracts and preventing tax fraud.

So if you didn’t adjust your plans for this Friday the 13th , and those plans have been negatively affected by someone who did, instead of cursing the world’s silly superstitions, consider being grateful for them. On balance, superstitions may make your world a better place.

Lucky you.