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."