Highly intelligent people tend to have these 8 unusual habits, according to psychology

When we picture “highly intelligent people,” it’s easy to imagine textbook smarts—high grades, academic awards, impressive careers.

But intelligence often shows itself in subtler ways, through everyday habits that don’t always look like brilliance at first glance.

In my own life, some of the smartest people I’ve met didn’t lead with big words or credentials. Instead, they had quirks—odd routines, unusual conversation patterns, even ways of thinking that set them apart.

And as I dug into the research, I found that psychology often backs these habits as markers of cognitive flexibility, creativity, and adaptability.

Here are eight unusual habits many highly intelligent people share—and what the science says about them.

1. They talk to themselves

It might look strange, but self-talk is actually linked to better problem-solving and self-regulation.

An interesting study found that talking yourself through a task out loud can improve focus and performance, especially when the instructions are complex.

This type of “verbal thinking” helps the brain organize information and monitor progress in real time.

The smartest people I know aren’t embarrassed to mutter through a tough problem—they use it as a tool. They know that hearing their own thoughts can make patterns and solutions stand out.

2. They embrace boredom instead of avoiding it

We live in a world where boredom is treated like a problem to be solved instantly—scroll, swipe, refresh.

But research suggests that moments of boredom can spark creativity.

That’s why it doesn’t faze highly intelligent people. They understand it’s fertile ground for daydreaming, reflection, and unexpected insights.

This brings me to the next point…

3. They daydream—on purpose

There’s a big difference between zoning out in a meeting and intentionally letting your mind wander.

Intelligent people often do the latter, and psychology has their back on this one.

According to a study by the Georgia Institute of Technology, people who reported more daydreaming instances scored higher on intellectual and creative ability and had more efficient brain systems. 

The researchers suggested that an efficient brain can switch into “idle mode” without losing track of the main task—almost like having a background app running that’s solving problems while you do something else.

For highly intelligent people, these mental detours aren’t wasted time. They’re a chance to connect dots, test out “what if” scenarios, and stumble on solutions that wouldn’t have shown up through straight-line thinking.

It’s why some of their best ideas seem to appear in the shower, on a walk, or while staring out a train window.

In other words, when their mind drifts, it’s often drifting somewhere useful.

4. They sleep at unusual times

Some highly intelligent individuals keep irregular hours, not because they’re lazy or undisciplined, but because they follow their own peak productivity rhythms.

Research has linked higher IQ to a preference for later bedtimes and wake times, a pattern known as “eveningness.”

While this doesn’t mean that being a night owl automatically makes you smarter, it suggests that intelligent people may feel freer to structure their schedules around when their minds work best—rather than conforming to a standard 9-to-5 body clock.

5. They question everything they believe

One of the most striking traits I’ve noticed in highly intelligent people is their willingness to doubt their own assumptions. They don’t treat beliefs as permanent—they treat them as working theories.

This mindset has been on my mind since I read Laughing in the Face of Chaos: A Politically Incorrect Shamanic Guide for Modern Life by Rudá Iandê.

His insights on inherited beliefs hit home: “Most of your ‘truths’ are inherited programming from family, culture, and society.” The book inspired me to look at how many of my own “certainties” were simply hand-me-down ideas I’d never examined.

Similarly, highly intelligent people aren’t afraid to update their worldview. They can hold the discomfort of not knowing while actively seeking better answers—and they often discover that the search itself changes them.

6. They swear more than you might expect

It’s a stereotype that people who swear lack vocabulary skills, but research has repeatedly challenged that assumption.

A study found that people who could produce more swear words in a timed test also scored higher on measures of overall verbal fluency.

For intelligent individuals, swearing can be less about aggression and more about expressive precision—it’s another tool in their linguistic toolbox.

They understand that sometimes, the “wrong” word is exactly the right one for the job.

7. They enjoy being alone

Being highly intelligent doesn’t mean being antisocial, but it often means needing more solo time.

Research in the British Journal of Psychology found that people with higher intelligence reported lower life satisfaction when they socialized more frequently—suggesting that too much interaction can be draining for them.

Time alone gives them the mental breathing room to think deeply, recharge, and work on personal projects without distraction.

It’s not about avoiding people—it’s about protecting their bandwidth and preserving mental energy for the work and relationships that matter most.

8. They collect seemingly “useless” knowledge

From obscure historical facts to niche scientific trivia, highly intelligent people often delight in learning things that have no immediate practical application.

While this might look like random curiosity, it’s actually a hallmark of “openness to experience,” a personality trait strongly linked to intelligence in research published in the Journal of Clinical and Experimental Neuropsychology. 

This wide-ranging curiosity helps them connect ideas across fields, which can lead to creative problem-solving and innovation. What seems “useless” today might become the missing puzzle piece tomorrow.

Final thoughts

Not all intelligent people have these habits, and having them doesn’t automatically mean you’re a genius.

But patterns like these hint at a mindset that values curiosity, self-awareness, and flexibility over conformity.

The smartest people I’ve met don’t just know a lot—they keep making room for what they don’t know.

They talk themselves through problems, welcome boredom, work when their brains are at their best, question their beliefs, speak freely, protect their solitude, and collect knowledge for the sheer joy of it.

And maybe that’s the real lesson here: intelligence isn’t just about processing information—it’s about how you live with the questions you haven’t answered yet.