15 signs you're smarter than you think you are

• Potential signs of high intelligence include being messy and worrying a lot.
• As it turns out, stupid people tend to overestimate their competence, while smart people tend to sell themselves short.
• Check out the list below and see if any of these signs apply to you.
• Visit Business Insider's homepage for more stories.

Stupid people tend to overestimate their competence, while smart people often sell themselves short. As Shakespeare put it in "As You Like It": "The fool doth think he is wise, but the wise man knows himself to be a fool."

That conventional wisdom is backed up by a Cornell University study conducted by social psychologists David Dunning and Justin Kruger. The phenomenon is now known as the Dunning-Kruger effect.

So, if you're not too sure about your own intellect, it actually might be an indication that you're pretty intelligent — thoughtful enough to realize your limitations, at least.

Here are some subtle signs that you are considerably smarter than you think.

Drake Baer and Chelsea Harvey contributed to a previous version of this article.

SEE ALSO: 11 common traits of highly intelligent people

You drink alcohol regularly

Evolutionary psychologist Satoshi Kanazawa and colleagues found that, among Brits as well as Americans, adults who had scored higher on IQ tests when they were kids or teens drank more alcohol more often in adulthood than those who had scored lower.

Some other studies support that finding as well, including a 2013 paper published in the journal Intelligence that found nations with a higher average IQ score also tend to drink more beer and wine. Interestingly, a 2013 study of young Swiss men found that moderate alcohol consumption was most strongly linked to high IQ.

You learned to read early

For a 2014 study, researchers looked at nearly 2,000 pairs of identical twins in the UK and found that the sibling who had learned to read earlier tended to score higher on tests of cognitive ability.

The study authors suggested that reading from an early age would increase both verbal and nonverbal (i.e. reasoning) ability, as opposed to the other way around.

However, a 2017 paper argued that the 2014 report didn't fully account for environmental and genetic factors that may have been driving the differences in intelligence.

You worry a lot

A growing body of research suggests that anxious individuals may be smarter than others in certain ways, according to Slate's coverage of several different studies on anxiety.

In one 2015 study published in the journal Personality and Individual Differences, for example, researchers asked 126 undergrads to fill out questionnaires in which they indicated how often they experienced worry. They also indicated how often they engaged in rumination, or thinking continuously about the aspects of situations that upset them.

Results showed that people who tended to worry and ruminate a lot scored higher on measures of verbal intelligence, while people who didn't do much worrying or ruminating scored higher on tests of nonverbal intelligence.