10 underrated signs of genuine intelligence (according to science)

Intelligence isn’t quite so clear cut. 

The truth is that it is multifaceted and so comes in many packages and takes on many guises. 

But science can shed some light upon how we measure and recognize intelligence. 

In this article we’ll take a look at 10 signs of intelligence. 

And I suspect that some of them are going to surprise you. 

So let’s dive in.

1. Being happy doing nothing

If you’ve ever been called lazy, it’s time to wear that label with pride. 

We live in an ever increasingly fast paced world. People always tend to be busy doing something. 

So much so that many struggle to sit back and do nothing. 

In his book ‘How to be Idle’ Tom Hodgkinson highlights how society can demonise a lack of so-called productivity:

“In 1993, I went to interview the late radical philosopher and drugs researcher Terence McKenna. I asked him why society doesn’t allow us to be more idle. He replied: I think the reason we don’t organise society in that way can be summed up in the aphorism, “idle hands are the devil’s tool.” In other words, institutions fear idle populations because an Idler is a thinker and thinkers are not a welcome addition to most social situations.”

One study, in particular, has backed up the idea that intelligent people are far happier being inactive. 

It found that smart people are less easily bored and so they are happy to spend time just thinking. 

2. Talking to yourself

I know, you probably weren’t expecting this one. 

But intelligent people don’t just spend a lot of time thinking, they think out loud too.

Total disclosure:

I was quick to include this sign as I do it all the time. 

In fact, people think I’m weird when I confess just how much I chat to myself. 

So I was very pleasantly surprised to stumble upon studies that found it could well be a sign of intelligence (rather than just a sign you’re a bit weird). 


Research concluded that it helps you to improve self-control. And it’s that which is a significant factor in intelligence. 

Scientists asked people to read instructions either silently or out loud to themselves. 

They discovered that those who read out loud had better concentration and performance levels. 

Maybe that’s why a study from Procedia Social and Behavioral Sciences noted that basketball players performed better when they gave themselves a pep talk. 

By uttering motivational affirmations to themselves (like “I can…” statements) they improved their game. 

Essentially, when we talk out loud to ourselves we find it easier to gain control. 

And as a 2009 study from Yale University showed, people with higher self-control tend to also have higher IQ’s. 

3. Being a worrier or struggling with mental health

So many of history’s greatest geniuses have also suffered with their mental health. 

As documented in the Psychiatric Times:

“Nikola Tesla was often mentally compromised, and Wolfgang Amadeus Mozart suffered from mood swings. Beethoven was periodically depressed; Tolstoy was a strange, otherworldly, idiosyncratic aristocrat; and let’s not forget the periodically outright psychotic, super-genius Isaac Newton.”

One scientific theory suggests that those with higher IQ’s also have a higher risk of physical and mental illnesses.

Research has shown “high IQ as being a potential risk factor for affective disorders, ADHD, ASD, and for increased incidence of disease related to immune dysregulation.” 

One of the reasons put forward as to why is that having a high IQ brain might make you hypersensitive to the environment. 

As a consequence you can be more prone to worry and anxiety that comes from overthinking. 

There is certainly evidence of a link between verbal intelligence and a tendency to worry or ruminate. 

Whilst similarly, another study drew a line between anxiety and having greater intelligence. 

4. Curiosity

We’ve just touched upon some of the potential downsides that can come along with intellect. 

But let’s turn ourselves back to the positives, because there are clearly many — including this next sign on our list. 

Intelligent people tend to be very curious.

Smart people like the new. They find it stimulating. So they enjoy refreshing and unconventional ideas.

Curiosity is what helps us all to grow our intelligence, regardless of any natural abilities. 

That’s because the more interested we are in the world around us, the more likely we are to learn. 

Research proves that your intelligence levels aren’t static or fixed. 

For example, one study showed that how we decide to invest both time and effort into our intellect makes a big difference. 

People who want to learn do so ultimately because they are curious. 

Studies have shown that both children and adults with high IQ’s were more curious and open to ideas. 

5. Being open minded

As we’ve just touched upon, being open minded is associated with higher levels of IQ too. 

For example, one study notes that young adults who consider themselves to be ‘very conservative’ had an average IQ of 95. 

Meanwhile those who instead described themselves as ‘very liberal’ had an average IQ of 106.

It seems that the most intelligent people amongst us manage to keep an open-mind to the views of others. 

This was backed up by a Yale University study done in 2008 that concluded that people who wait to make their mind up are smarter. 

They can take on board diverse information rather than being quick to jump to conclusions. 

6. Adaptability

To a certain extent, the very survival of human beings has relied upon this next sign of intelligence. 

That’s being able to adjust to new conditions

Life is bound to throw curveballs. Let’s face it: life is chaos. 

Stephen Hawking has often been quoted as having said:

“Intelligence is the ability to adapt to change.”

Actually, whether he ever did or not is still open for debate. But it does point out how fundamental adaptability it is. 

Research has pointed to the fact that intelligence relies on the ability to change your behaviour. 

That way you not only function more effectively in your environment but you can even make changes to the environment you’re in.

Adaptability relies on plenty of demanding cognitive processes like perception, memory, learning, reasoning and problem solving. 

Yet another reason why it’s a sign of intelligence. 

7. Empathy

One of the false images we can have about intellect is that it is robotic, unfeeling and almost frostily logical. 

That’s why empathy may not be one of the first signs of intelligence that springs to mind. 

Yet there is a strong correlation between the two. 

As discussed in Science Direct:

“Highly intelligent children are more likely to develop higher levels of empathic skills because they are more sensitive to other people’s emotional cues, and are better able to understand other people’s thoughts and feelings.”

The study ultimately concluded that smarter people are more prosocial. 

8. Enjoying time alone 

As we’ve just hinted to, we humans are social creatures. 

We value relationships and we rely on one another for not only our survival, but often many of our emotional needs. 

Yet when scientists took a look at the potential impact of friendship, population density, and intelligence on happiness they found something intriguing

Highly intelligent people are often loners. Their self-reliance causes them to spend plenty of time on their own. 

One of the authors of the study, Satoshi Kanazawa explains why:

“In general, more intelligent individuals are more likely to have ‘unnatural’ preferences and values that our ancestors did not have. It is extremely natural for species like humans to seek and desire friendships and, as a result, more intelligent individuals are likely to seek them less.”

9. Not thinking that you know it all 

It’s official, humility is way more compatible with intelligence than arrogance. 

There’s an important link between being humble and being smart. 

And the fundamental reason is summed up rather poetically in the following quote often attributed to Socrates:

‘Intelligent individuals learn from everything and every one; average people, from their experiences. The stupid already have all the answers.’ 

Being ignorant of your own ignorance is what makes you dumb. 

Studies show that the least bright people tend to overestimate their abilities. 

This cognitive bias stops you from understanding your own limitations. 

But intelligent people know they don’t know it all. 

This is what keeps them open to learning and growing.

10. You’re observant and good at remembering things

How good your memory is can be a skill in which you build upon. 

But it’s also something that has been linked with intelligence levels

For example, one study showed it has a strong relationship with so-called fluid intelligence — aka your ability to reason and think abstractly.

Memory and observation skills certainly can be linked. A good memory means you have the ability to pay attention. 

Similarly, different forms of observational skills have also been associated with different types of intelligence

Dr. Catherine Jackson, clinical psychologist says:  “In a world where people talk to prove who they are, highly intelligent people are the opposite,”. 

Instead, they prefer to absorb and take everything in, which helps them to spot things other people may miss.  

Louise Jackson

My passion in life is communication in all its many forms. I enjoy nothing more than deep chats about life, love and the Universe. With a masters degree in Journalism, I’m a former BBC news reporter and newsreader. But around 8 years ago I swapped the studio for a life on the open road. Lisbon, Portugal is currently where I call home. My personal development articles have featured in Huffington Post, Elite Daily, Thought Catalog, Thrive Global and more.

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