Why Smart People Believe Dumb Things

Ever argued with someone who’s obviously wrong—but they’re absolutely convinced they’re right? Maybe you’ve thought, “How can they believe that nonsense?” Well, here’s the uncomfortable truth: we all believe dumb things.

Even the smartest among us—scientists, scholars, and seasoned professionals—fall into mental traps that make us cling to bad ideas. And no, it’s not just ignorance or lack of intelligence. It’s how human brains are wired.

So, why do we do this? And more importantly, how can we stop?

The Brain’s Shortcuts: Useful but Dangerous

Our brains are built for efficiency, not perfect reasoning. Instead of carefully analyzing every piece of information, we rely on cognitive shortcuts to make quick decisions. Most of the time, this works well. But sometimes, these shortcuts lead us straight into confirmation bias, groupthink, and other mental pitfalls.

Confirmation Bias: The Ultimate Yes-Man

People tend to favor information that confirms what they already believe. This is known as confirmation bias, and it’s one of the most common ways we deceive ourselves.

If someone believes electric cars are terrible, they will only seek out articles about battery fires and ignore studies showing their benefits. If another person believes a certain politician is corrupt, they will only pay attention to news that supports that view while disregarding any counterarguments. The brain does this to avoid cognitive dissonance, the discomfort of holding two conflicting ideas. It’s easier to dismiss contrary evidence than to reconsider a stance.

The best way to fight confirmation bias is to actively seek out information that challenges existing beliefs. Reading opposing viewpoints, following news sources from different perspectives, and asking, “What would it take to change my mind?” are all ways to counteract this mental trap.

The Dunning-Kruger Effect: The Confidence of the Uninformed

The less people know, the more they think they know. This is called the Dunning-Kruger effect, and it explains why beginners often overestimate their abilities.

A person who watches a few YouTube videos about investing might suddenly believe they have mastered the stock market. Meanwhile, an actual economist is more cautious because they understand the complexities and risks involved. Beginners lack the experience to recognize their own ignorance, while experts tend to underestimate their knowledge, sometimes leading to impostor syndrome.

One way to combat this effect is to recognize that confidence does not equal competence. Staying humble, continuously learning, and asking more questions than providing answers can help avoid falling into this trap.

Groupthink: The Power of the Tribe

Humans are social creatures, and the desire to fit in can override rational thinking. Groupthink occurs when people conform to the opinions of the majority, even if they suspect those opinions are wrong.

In the 1950s, psychologist Solomon Asch conducted an experiment where participants were asked to complete a simple visual test. When actors in the group intentionally gave the wrong answer, 75% of participants went along with them at least once, despite knowing it was incorrect. This experiment showed how powerful the need for social acceptance can be, even in low-stakes situations.

To resist groupthink, people should be aware of when they are agreeing just to maintain social harmony. Surrounding oneself with those who challenge ideas and practicing saying, “I disagree, and here’s why,” can help break free from this psychological pressure.

The Sunk Cost Fallacy: Sticking with Bad Decisions

People often continue with bad decisions simply because they have already invested time, money, or effort into them. This is known as the sunk cost fallacy.

Someone who has spent years in a job they hate may feel compelled to stay because they have already put in so much work. A person halfway through a terrible movie might refuse to turn it off because they have already watched an hour of it. The fear of admitting a mistake often outweighs the discomfort of persisting in a bad choice.

One way to counteract this fallacy is to ask, “If I were starting fresh, would I still choose this?” Recognizing that past investments do not dictate future decisions makes it easier to cut losses and move on.

So, What Can Be Done?

Biases cannot be completely eliminated—they are part of being human. But they can be recognized and actively challenged.

Next time an idea feels immediately right or wrong, it’s worth pausing to ask whether it is being accepted because it is true or because it is convenient. The smartest people aren’t the ones who always know the answer. They are the ones who know when to question themselves.