When I was a kid, my grandma used to say, “If it rains on the first day of the month, it’ll rain at least fifteen days that month.”
Now, I was a kid, but I was that kid… you know the one: “Actually…”
Despite my evangelical Christian upbringing, my thoughts immediately went to science. If she’d said “on the equinox” or “on the solstice,” it would have been different; those are days when the sun and the earth are in specific positions. The first of the month, however, is just a human designation for measuring time—and it’s not even perfectly accurate. Our year is a quarter of a day off, which is why every four years we add an extra day to February and call it a “leap year.”
Eventually, I challenged her. I told her that the first day of the month was an arbitrary human label and wasn’t connected to anything that would scientifically result in more rain. Her response? Get a calendar, mark the days, and see for yourself.
I did. The next time it rained on the first of the month, I started marking the days.
Guess what?
Yup. It rained more than fifteen days that month.
After that, I stopped challenging Grandma on her “sayings.”
But… was it actually true, or did I just happen to pick the right month?
Confirmation Bias
It rains on the first of the month. Someone cites the old adage: “If it rains on the first day of the month, it’ll rain at least fifteen days that month.” Most people don’t track it the way I did as a kid, but we all notice when a month happens to be particularly rainy. One day, amidst a downpour, someone says, “Well, Uncle Jimbo said this would happen because it rained on the first.” Everyone nods in agreement.
Had it not rained much that month, people wouldn’t have given the adage a second thought. But the rain serves as a reminder. When the prediction comes true, it feels like it always happens… because that is all we remember.
This is confirmation bias: the tendency to search for, interpret, favor, and recall information in a way that confirms one’s preexisting beliefs or hypotheses. We all do it to some degree. Bear in mind, our brains evolved over hundreds of thousands of years in environments where assessing information—especially potential threats—was a matter of life or death. It’s not a defect; it’s a “heuristic.”
Wikipedia defines a heuristic as “any approach to problem solving that employs a pragmatic method that is not necessarily optimized, perfected, or rationalized, but is nevertheless ‘good enough’ as an approximation.” If “good enough” means our ancestors jumped at a shadow nine times out of ten, but the tenth time that shadow was a sabre-toothed cat and they narrowly avoided becoming dinner, then it sounds “good enough” to me.
Essentially, your brain acts as a filter: it lets in information that fits your current worldview (which feels rewarding and safe) and filters out or discounts information that contradicts it (which creates cognitive dissonance or psychological discomfort). If you live where there are deadly snakes, scientific accuracy isn’t the priority—erring on the side of caution is.
“Every time I go berry-picking in that patch north of the cave, I see a snake.”
Go three times in a row and don’t see a snake? “Well, today was a lucky day.” See a snake the fourth time? “Yup, I told you! Every time I go up here to pick berries, I see a snake!”
But how does this relate to the rest of us?
“Whenever I’m running late, every traffic light is red.”
If you’re running late, you’re in a hurry. If you’re in a hurry, you notice—and are likely frustrated by—anything that slows you down. If you weren’t in a hurry, a red light would be meaningless, and you wouldn’t take note of it.
Consider someone who is convinced they have a specific medical condition after reading a few symptoms online. When they search for more information, they will likely ignore the ten articles that say “these symptoms are common signs of stress” and focus intently on the one rare article that suggests a serious disease. They confirm their fear by selectively picking data that supports the scary diagnosis while dismissing the more likely, benign explanations.
Or, say you’ve just met someone and they say something that you interpret as a sign of arrogance. For the rest of the conversation, you will interpret their confidence as arrogance. If they speak clearly about their achievements, it confirms your bias. If they are quiet, you might interpret it as them thinking they are “too good” to talk to others. You are no longer observing the person objectively; you are hunting for evidence to support your initial judgment.
“Jenna is such a slacker; every time I see her, she’s at the coffee pot.”
Except Jenna gets that coffee and goes back to her desk to pound out work for an hour. You have this idea in your head about “Jenna,” and seeing her at the coffee pot confirms it. Seeing her elsewhere is just an exception. Of course, you share this sentiment with a few coworkers and—lo and behold—now they’re noticing Jenna at the coffee pot, too.
This is the sort of bias that can be deeply damaging to the subject. If we want to make the best choices, we have to resist what feels natural and think twice.
Mitigating Confirmation Bias
It is easy to look for evidence that supports our beliefs. If an issue is truly important, try spending time actively seeking out information that contradicts your current view. For instance, we all know there are people who believe the Earth is flat. A quick search for “evidence that the Earth isn’t flat” provides a wealth of information. Were I a flat-earther, I could read these counter-arguments and think them through for myself. In that case, I’d want to avoid regurgitating responses I’d been told by others and instead evaluate the logic of the opposing view.
You can also try the “Devil’s Advocate” approach: When making a major decision, assign yourself (or a friend) the role of the critic. Force yourself to argue the opposite side as convincingly as possible. (Also, this could be a great party game for nerds like me!)
Finally, pause and reflect. When you feel a surge of satisfaction from finding a piece of information that proves you are right, stop. Ask yourself: “Am I valuing this information because it is accurate, or because it makes me feel validated?”
