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How do you know someone is actually smart? Some intelligent people exude confidence, but plenty of not-very-smart people speak confidently about things they actually have no expertise in. On the other hand, some genuine geniuses are so humble and unassuming that it takes a while for others to realize the depths of their knowledge, and having more questions than answers can actually be a sign of a brilliant mind.

Highly intelligent people come in all types, but certain hallmarks of intelligence are noticeable in how smart people approach people and situations. Sometimes those hallmarks are things people might think are unrelated, such as having a great sense of humor, and others are the opposite of what people might think of as smart people traits.

A Redditor asked people on the ProductivityCafe subforum to share the “subtle signs that someone is intelligent," which led to great conversations about the characteristics of intelligent people and how their smarts seem to influence every part of them, from their personality to their ability to avoid unnecessary conflict.

Here are 14 subtle signs people shared that someone is very intelligent.

1. Curious about multiple subjects

"They like to learn about any and everything."

"And remember details and concepts later. A desire to understand and curiosity about the subject at hand."

2. They change their minds

"They can change their mind when presented with new information."

"This is definitely the best / most noticeable answer. Intelligent people agnostically process new information. They don’t just “automatically” deny anything that they don’t know or is inconsistent with what they already know. Intelligent people - it’s not what they know, it’s how they interpret / process new information."

"As John Nash, the mathematician allegedly once said; when the facts change, I change my mind!"

Quick wit and a good sense of humor can be signs of intelligence.Photo credit: Canva

3. They process humor quickly

"They get the joke sooner than most people. Happens once in a while in movies or group settings: one person starts to laugh way ahead of everyone else. That’s one with a super fast processing mind (I know one). It is totally unconscious, so cannot be faked."

4. They like being corrected

"When you correct them, they're actually happy about it because they get to learn something new."

"100%. This is often referred to as growth mindset."

5. Great sense of humor

"Humor is a marker for intelligence. Truly dumb people aren’t funny."

"Agreed but I would add that witty or dark humor is more intelligent than mean, cruel, gross humor. If someone’s 'wit' is just the same structure of putting other people down or being gratuitously shocking or gross, then no."

"A really good sense of humor. To be really funny, you have to be very observant and able to see things in ways that others don’t."

6. They make you feel smart

"They explain some things to you in a way that makes you feel intelligent."

"Einstein said, 'If you can't explain what you are talking about to a six-year-old, you don't fully understand it yourself.'"

Smart people take time to think before responding.Photo credit: Canva

7. They think before they respond

"They don't react. There is always a delay... and then, they respond."

"They observe, they pause, and then comes the long encyclopedic reply."

8. They know when to be quiet

"Yes, I have come across people with no filter, and have to argue about everything, and that can be exhausting."

"Never miss a good opportunity to shut the f**k up."

9. They're great at banter

"Yes, and quick word play/good puns."

10. They ask about your thought process

"If someone is inquisitive. They want to know how and why you think the way you do. Most people don’t do this."

11. They know what they don't know

"Even very intelligent people don't know about every topic. They understand this and don't pretend to be an expert or speak to things they don't specialize in. Or they use analogies to connect it to things they do understand. They understand that there is a lot they do not know, especially about their given specialties."

"Some people have so much ego, that they have an inability to say that they don’t know the answer to a question. They’ll either give a bullsh*t answer, or try to shrug off the patient’s concerns entirely. Nobody knows everything. If you don’t know, there’s no fault in admitting that, and then using resources to find the answer."

There are multiple manifestations of intelligence. Photo credit: Canva

12. Physical intelligence is important, too

"I wish people could understand intelligence in many forms—being good with your hands is intelligence. Being able to learn elaborate choreography is intelligence. Being emotionally responsive and understanding microexpressions is intelligence. It’s not just regurgitating facts. I’m a fact regurgitator myself, but I have a lot of respect for things I can’t do."

13. They don't get into drawn-out arguments

"Not raising their voice during a disagreement. Shouting over each other is to try and win an argument with intimidation rather than logic."

"Argue with an idiot and there's two idiots."

14. They think for themselves

"They don’t have herd mentality. Specifically in politics, religion, and pseudoscience."

"I remember the first time that I understood that not picking a side was a valid option for many situations. It was like a record skip moment in my head."

There are other signs of intelligence that people shared, of course, some of which are hilariously debatable. For instance, someone claimed that intelligent people use bidets instead of toilet paper, which is awfully specific and subjective. While certainly not foolproof, the above traits offer some solid starting points for spotting a smarty among the masses.

This article originally appeared last year. It has been updated.