“The cause of my life has been to oppose superstition. It’s a battle you can’t hope to win — it’s a battle that’s going to go on forever. It’s part of the human condition.”

— Christopher Hitchens

Superstitions are our brain’s way of making sense of a perplexing world. Over time, as we learn nature’s truths and laws, we leave less space for the guesswork of superstition. In considering the causes of health problems, we replace our beliefs in evil spirits with our knowledge of viruses and organ failures. In putting defendants on trial, we replace our witch dunking with courts and evidence. Generally speaking, the loss of superstitions is a sign of progress. But that doesn’t mean superstitions never have value.

What do we mean when we use the word “superstition”? We are superstitious when we wrongly identify the cause of a particular effect, especially when we invoke a supernatural belief or myth in that estimation. Let’s take the example of a car accident caused by a drunk driver. If we initially assumed that the accident was caused by the car’s faulty brakes, then we would just be wrong. But if we assumed it was caused by a ghost who possessed the driver, we would be superstitiously wrong.

The difference between “wrong” and “superstitious” essentially comes down to how sensible we are in our guesses and judgments. Many car accidents are caused by faulty brakes, and we can find evidence of brake failure after the accident. But we will never find evidence of a ghost, and so far, there hasn’t been a recorded accident that was reliably attributed to ghostly behavior.

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Given the bizarre and often disastrous consequences of superstition, from the historical killings of innocent “witches” to the bloodletting treatments for asthma, it may seem foolish to consider whether superstitions offer an advantage to humanity. But in reality, superstitions are simply an overextension of our desire to find truth in the world.

Where do we draw the line in our decision-making about whether A caused B? Imagine a deer on a savanna that hears a rustle in the grass beside it. Could that rustle be a lion that is preparing to pounce or is it just the wind? This is clearly an important decision; the deer’s life rests on it. The cost of wrongly believing that the rustle came from a lion when it just came from the wind is the wasted energy involved in running away. The deer could have stayed calm and continued to enjoy the fresh grass. In contrast, the cost of wrongly believing that the rustle came from the wind when it came from a crouching lion is far more catastrophic. Your flesh will be ripped right from your bone. So we can forgive deers for being a little skittish.

The deer could develop a superstitious belief when calculating whether the rustle of a tree’s leaves is caused by a lion. Let’s assume that there is absolutely zero chance that a tree’s rustling could predict a lion, because the lions on this particular savanna cannot climb trees. Then it makes sense for the deer to completely ignore the noise of a tree. The problem is that the rustling of a tree can sound similar to the rustling of grass. If the association between rustling grass and a pouncing lion is strong enough, and if the sounds of rustling trees and rustling grass are similar enough, then the deer may leap into a sprint when a nearby tree is shaken by a gust of wind. We might call that connection, between the sound of a tree and belief in a nearby lion, a superstition.

If we have a trigger-happy brain that believes anything causes anything, we will undoubtedly hit the correct answer occasionally, but we’ll end up in the impractical situation of working through infinite incorrect pairings of cause and effect. Anything from trees to trifles will set off our alarm bells about some problem we have. Maybe yesterday’s rain caused my headache. Maybe the apple I ate caused my headache. Maybe the cat’s sneeze caused my headache. If my head feels better tomorrow, maybe the bloodletting today worked! Any existing association becomes fair game in judging causality.

On the other hand, if we have a brain that waits for only the clearest and most foolproof evidence of an association between events, then it will take us a long time to get to any answer at all because the world is such a noisy mess. When we are too conservative in our decision-making, it prevents us from experimenting with an efficient process of trial and error, and it might even lead us to ignore dangerous signals in our environment because we’ve failed to notice their significance.

“Superstition is foolish, childish, primitive and irrational, but how much does it cost you to knock on wood?“

— Judith Viorst

So the optimal solution for our brain is somewhere in the middle between overenthusiastic and over-skeptical causal inference. Researchers have experimented with different models for explaining superstitions. They suggest that superstitious thinking may be biologically helpful when the correct answer to a particular problem would give us an enormous advantage for survival. In those high-stakes situations, any causal inference may be better than no causal inference. In other words, running away from harmless rustling trees may be an adaptive superstition when rustling grass can cause our immediate death.

At one point in human history, we began to believe that green ornamental beads were useful for warding off evil and enhancing fertility. The onset of these superstitious beliefs overlapped with our transition to agriculture. The green color associated with healthy crops and fertile ground may have led to the green color associated with happiness and fertility in good luck charms. So perhaps the superstitious associations that explain a deer running from rustling trees can also explain our historical attraction to the color green.

Photo by  Amy Reed  on  Unsplash

Photo by Amy Reed on Unsplash

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The ambiguities in our decision-making highlight why superstitions are relevant from the perspective of evolution. Natural selection doesn’t necessarily care about perfection: it just happens upon sufficient functionality for survival. Superstitions can appear under that umbrella of sufficient functionality.

In contemporary human life and culture, superstitions may have another curious interaction with our behavior. When you think about some of the most superstitious people you know, athletes may spring to mind.

One of the annoying mysteries about human athletic performance is why it’s so variable. Why, even after years of practice and expertise, do we still fail at basic tasks like throwing balls into baskets, kicking balls in goals, and jumping over hurdles? Even the best of the best struggle to reach 100% accuracy with precision actions, despite practically dedicating their life to the activity.

Part of the story behind our imprecise movements lies with our noisy motor control systems. Our brain is a hodgepodge of functions and incremental evolutionary improvements, and it is a messy rather than technically perfect machine. When we look at brain activity during any action, we find a substantial portion of irrelevant activity that we call “noise”.

A lot of the noise in our brain may be important activity that we can’t quite understand yet. For example, spontaneous and random-looking activity could be relevant in the creativity and behavioral flexibility that make human psychology so special. But some portion of the noise is also likely to be mess that interferes with the specific actions we want to plan.

When it comes to performing specific physical actions, the noise in our brain may be partly responsible for our variability and inconsistency. When researchers recorded the activity of individual neurons in motor areas of the brain while monkeys prepared to reach toward objects, they found that variability in noisy activity predicted how the arm actually moved. So we can blame the noise in our motor cortex next time we miss that basketball free throw or golf putt.

Elite athletes seem to have some awareness of this problem. Many of them engage in superstitious behaviors before a big game, or when preparing for an athletic burst of energy. Michael Jordan wore the shorts from his college basketball team under his Bulls uniform during every game, Turk Wendell brushed his teeth before baseball innings, and Serena Williams wears the same pair of socks throughout a tournament and bounces the ball five times before a first serve.

The best thing about these kinds of superstitions is that they seem to work. They can improve self-belief and confidence, leading to stronger persistence. They may also help athletes gain a greater sense of control over their environment. The last thing you want to do when you’re on a hot streak is introduce some irrelevant factor that might unintentionally change your behavior. So wearing the same clothes and performing particular action rituals may be an athlete’s way of reducing the levels of noise in their environment, and consequently their brains. Watch Hal’s bowling below for a great insight into the origins of superstitious beliefs.

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“Science is the great antidote to the poison of enthusiasm and superstition.“

— Adam Smith

Our superstitious styles of thinking are grounded in a long evolutionary history of problem-solving. They reflect the balance between our need for caution and our need to find answers. Sometimes, there are surprisingly rational benefits to functions that seem wholly irrational. By taking notice of them, we better understand the oddities of the human condition.

In modern developed countries — the safest and healthiest societies we’ve built so far — superstitions have a narrowing scope in which to operate. They thrive in dark rooms, where we clumsily stumble around trying to find answers without the support of strong evidence-based ideas and models that explain the world. The Enlightenment, and our continuing advancements in science and reason, shine a beaming light into that dark room, revealing the corners in which our superstitions used to hide. We can breathe a sigh of relief every time we visit a great doctor, knowing that she is unlikely to prescribe bloodletting or alchemy for our chesty cough.