Smart people aren't just defined by their outrageously high scores on IQ tests.
They tend to share a bunch of other characteristics, like insatiable curiosity and a good sense of humor.
We took a look at a Quora thread where users have listed some common traits of highly intelligent people, and checked out the science to see if it backs them up.
Here are 11 qualities of super smart people:
They're highly adaptable
Several Quora users noted that intelligent people are flexible and able to thrive in different settings. As Donna F. Hammett writes, intelligent people adapt by "showing what can be done regardless of the complications or restrictions placed upon them."
Psychological research supports this idea. Intelligence depends on being able to change your own behaviors in order to cope more effectively with your environment, or make changes to the environment you're in.
They understand how much they don't know
The smartest folks are able to admit when they aren't familiar with a particular concept. As Jim Winer writes, intelligent people "are not afraid to say: 'I don't know.' If they don't know it, they can learn it."
Winer's observation is backed up by a classic study by Justin Kruger and David Dunning, which found that the less intelligent you are, the more you overestimate your cognitive abilities.
In one experiment, for example, students who'd scored in the lowest quartile on a test adapted from the LSAT overestimated the number of questions they'd gotten right by nearly 50%. Meanwhile, those who'd scored in the top quartile slightly underestimated how many questions they'd gotten right.
They have insatiable curiosity
Albert Einstein reportedly said, "I have no special talents, I am only passionately curious."
Or as Keyzurbur Alas puts it, "intelligent people let themselves become fascinated by things others take for granted."
Research published in 2016 in the Journal of Individual Differences suggests that there's a link between childhood intelligence and openness to experience — which encompasses intellectual curiosity — in adulthood.
Scientists followed thousands of people born in the UK for 50 years and learned that 11-year-olds who'd scored higher on an IQ test turned out to be more open to experience at 50.
They read a lot
Because they're so curious, smart people are also inclined to be voracious readers, writes Cheikh Mbacke Diop.
Indeed, many of the world's most successful people— Bill Gates and Oprah among them — say they educate themselves by reading anything they can get their hands on.
Smart people don't close themselves off to new ideas or opportunities. Hammett writes that intelligent people are "willing to accept and consider other views with value and broad-mindedness," and that they are "open to alternative solutions."
Psychologists say that open-minded people — those who seek out alternate viewpoints and weigh the evidence fairly — tend to score higher on the SAT and on intelligence tests.
At the same time, smart people are careful about which ideas and perspectives they adopt.
"An intelligent mind has a strong aversion to accepting things on face value and therefore withholds belief until presented with ample evidence," says Alas.
They like their own company
In a since-deleted answer, Richard He points out that highly intelligent people tend to be "very individualistic."
They have high self-control
Zoher Ali writes that smart people are able to overcome impulsiveness by "planning, clarifying goals, exploring alternative strategies and considering consequences before [they] begin."
Scientists have found a link between self-control and intelligence. In one 2009 study published in the journal Psychological Science, participants had to choose between two financial rewards: a smaller payout immediately or a larger payout at a later date.
Results showed that participants who chose the larger payout at a later date — i.e., those who had more self-control — generally scored higher on intelligence tests.
The researchers behind that study say that one area of the brain — the anterior prefrontal cortex — might play a role in helping people solve tough problems and demonstrate self-control while working toward goals.
They're really funny ...
Advita Bihani points out that highly intelligent people tend to have a great sense of humor.
Scientists agree. One 2011 University of New Mexico study found that people who wrote funnier cartoon captions scored higher on measures of verbal intelligence. Another University of New Mexico study found that professional comedians scored higher than average on measures of verbal intelligence.
... and they appreciate dark humor
Elora Amber mentions research that suggests intelligent people have a "twisted sense of humor."
Indeed, a 2017 study published in the journal Cognitive Processing found that people who score higher on tests of verbal and nonverbal intelligence are most likely to enjoy and understand "black humor." (For example: "Here is the answering machine of the self-help association for Alzheimer patients. If you still remember your topic, please speak after the tone.")
Those who appreciated the dark humor did not, however, appear to be in any way disturbed or aggressive.
They're sensitive to other people's experiences
Smart people can "almost feel what someone is thinking/feeling," He added in the deleted answer.
Some psychologists argue that empathy, being attuned to the needs and feelings of others and acting in a way that is sensitive to those needs, is a core component of emotional intelligence. Emotionally-intelligent individuals are typically very interested in talking to new people and learning more about them.
They think outside the box
Being smart is about thinking differently.
Teodora Motateanu writes that highly intelligent people "question the status quo. They question the old ways to do things. They have unusual, out of the box, apparently 'crazy' ideas."
In fact, sticking to the status quo may sabotage your success. Scott Galloway, a clinical professor of marketing at New York University's Stern School of Business, previously told Business Insider that successful people (like successful companies) are always asking, "What if we did it this way?"
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