Intelligent People Possess These 3 Surprising Traits—Do You?

Measuring intelligence doesn’t always come in the form of an IQ test.

While being a card-carrying Mensa member may prove that someone is smart on paper, it doesn’t exactly reveal how adept they may be at other brain-powered skills (like thinking creatively), nor does that certification make intelligence easy to spot right off the bat. (This is especially key if “quality over quantity” is your philosophy to making friends.)

As Insider reports, there’s plenty of research to suggest how brainiacs develop their gray matter—and some of these signs are more apparent to the naked eye than others. Below, explore three surprising traits that intelligent people possess.

They’re the Oldest Child

Oldest children tend to have slightly higher IQ scores than their younger siblings, but their intellectual advantage may have more to do with family dynamics than genetics. In a 2007 study examining birth order, health, and intelligence, Norwegian epidemiologists found that the average first-born had an IQ score of 103, while the second child scored 100, and the third scored 99.

The findings revealed that older children who are expected to tutor their younger siblings often mature intellectually as a result.

They’ve Had Their Share of Vices

Ever wonder why seemingly smart people make poor decisions when it comes to unhealthy vices? According to a study in Britain, 11-year-old children with high IQs were more likely to use illegal drugs or drink alcohol excessively in adulthood. While this revelation is by no means an excuse to order up another shot (or five), it may explain why some intelligent people have their fair share of vices.

They’re Left-Handed

It’s often believed that left-handed people are more creative and have criminal minds. There may be some truth to both beliefs as it pertains to intelligence, as this research from 1995 showed an association between left-handedness and “divergent thinking.”

In a study of left-handed men, researchers discovered that the southpaw test subjects were more creative problem-solvers.

Head over to Insider for more surprising signs of intelligence, and share your thoughts on the findings below!