There are significant reasons to size up a person’s mental acuity. For example, if you are taking advice, interviewing, or communicating, it helps to know what you are working with. Many of the best managers are excellent at reading their audience.

If you are looking for a one-shot way to determine brilliance, stop reading now. If you are looking for exceptions to the following points, you’ll be able to find them. The following are correlative, not causal. This is an exercise in nuance. Because within nuance, you find most answers.

They Practice Intellectual Humility

I worked in finance and mostly hated it. However, one of the few perks was the people. The industry attracts and needs intelligent people. Consequently, hiring successful candidates mandated we get a quick read on them. Interviewing is tricky because everyone is putting their best foot forward and trying to sound smart, as perhaps they should.

A manager taught us a trick: ask a question the candidate won’t know the answer to. Then, observe how they act. A very good sign was when they could simply admit they didn’t know, rather than fake it and force-feed an answer.

This admission is a sign of intellectual humility, which is correlated to better decision-making. This is particularly useful in an industry plagued by arrogance. Intellectually humble people challenge their conclusions based on evidence and feedback from others. As a simplistic example, you’ll see this when people say, “From what I’ve seen, it could be true.” Rather than, “It’s definitely true.” They frame their observations as open to critique. They prize truth over ego.

Obvious Signs are Often a Valid Data Point

For example, people who refuse to social distance tend to be less intelligent. People who read in their free time skew smarter than those who don’t. Things that smart people tend to do, tend to be done by smarter people.

Many years ago, I was working retail at a used sports equipment store. A 10-year-old kid came in to buy a baseball helmet. I gave him the price. He held the helmet up, looked it over, then looked back at me, “Can you knock a few bucks off? I mean, look at these dents.” He pointed at the dents. I smiled and gave him a discount.

When he left, I thought, “That kid is going to do just fine.” Being crafty, demonstrating street smarts, and quick thinking is correlated to intelligence. In fact, Yale scientists found that street smarts are just as important for employees as their academic smarts. More plainly, you can be a mediocre student, with great street smarts, and go on to be very successful.

They are Meta, Literally

There is a newly popular phrase, “That is so meta.” Meta means something is self-referential. For example, a Medium article that is about Medium articles is meta. A video game where you play a character playing a video game is meta. The Onion famously did this with “World of World of Warcraft.”

Related to this, intelligent people often demonstrate metacognition. They talk about and analyze their own thought process. They are objective and critique their nature. They know when and how they perform best. A simple example of meta behavior is when someone says, “I need to put this on my calendar or I won’t hold myself accountable.” Unsurprisingly, people with high metacognition are often great students and employees. They leverage their self-awareness to their advantage.

They Know what Killed the Cat

Intelligent people tend to be curious. They have an itch to know more, to drill down on details, just for the sake of knowing. After all, that’s how we learn, right?

Curiosity is an indicator of intelligence in other animals too. For example, there was a study involving three language-trained chimps. Their job was to use a keyboard to name what food was in an unreachable container. The prize was, you guessed it, food. When the test food was visible, they just hit the correct button and got the food. When the food was hidden amongst various containers, the smarter chimps inspected and tried to peek inside the containers before giving their answers. They knew the odds of winning were higher if they learned more.

This chimp study is a basic example but reveals the power of information seeking (curiosity). And don’t forget, we share 98.8% of our DNA with chimps. The smartest chimps are measured by their ability to patiently learn and troubleshoot problems. Sound familiar?

The Strongest Indicator of Intelligence

My dad was an engineering major at the Naval Academy decades ago. He doesn’t brag very often about other men. It takes a lot to impress him. But one of his roommates, Charlie was a special classmate.

They were both in an industrial engineering class. It was the hardest class he’d ever taken. Dad said they’d come back to the room. He’d study for hours while Charlie only studied 20 minutes and then fiddled with his guitar. That roommate still got better grades than my dad, who is fairly bright, and it ticked him off to no end. That roommate went on to become a college professor.

At the pulsing core of intelligence is the ability to simplify complex problems and solve them, as Charlie did. Often, that skill is genetic. The people themselves don’t know how they do it. You can develop the skill as well. A physics professor once told me that, “A big problem is just a bunch of small problems combined. Learn to separate them out.” It’s all a matter of approach.

Conclusion and Takeaway

Society has placed a massive priority on intelligence. We often feel pressure to be smart and value those who are. Never forget the value of kindness and respect. Each person has their own combination of skills and gifts and should be respected as such.

Remember, outside of a psychologist-provided test, there’s no real way to gauge intelligence in one data-point. But if they do these five things, there is a very good chance they are quite smart.

1.They demonstrate a curiosity to learn more information.

2.They can openly admit when they don’t know something. They know and operate within their limits.

3.They can break down complex problems and cut straight to a solution.

4.They have an acute awareness of their own thought process. They critique and understand it. They use that knowledge to their advantage.

5.They display obvious signs of intelligence. They think quickly on their feet and have situational awareness. They wear a mask during a pandemic.