Jeff Bezos says the number one sign of high intelligence is a willingness to change your mind -- a lot. He looks for people who can admit they are wrong and readily change their opinions.

That's great, but just like the famous survey where more than 80 percent of respondents said they were above-average drivers -- which is mathematically impossible, and all the respondents had been injured in car accidents, which is pretty darned ironic -- most of us think we are willing to change our minds when better data, better evidence, or a better point of view comes along. 

Here are some other signs you may be smarter than you think you are:

1. You like to spend time alone.

While people who socialize more tend to be happier, that's not true if you're highly intelligent. In that case, socializing with friends will not increase your level of satisfaction with your life.

Researchers followed people between 18 and 28 years old and found the more frequently the average person socialized, the happier they were -- but not the subset of people studied who were highly intelligent.

The more they socialized, the less happy they were.

One theory is aspirational: The smarter you are, the more focused you will be on longer-term goals, and spending time with friends is distracting rather than helpful.

So if you like to spend time alone to work on a project, to learn something new, to write that business plan, or to grind away at all the steps you need to take to reach your goals, don't assume you're a loner.

You may simply be smarter than the rest of us.

2. You often think you're wrong.

We all know people who take a position, and then proclaim and bluster and pontificate while totally disregarding differing opinions or points of view. They know they're right -- and they want you to know they're right.

Their behavior isn't an indication of intelligence, though. It's the classic sign of the Dunning-Kruger effect, a type of cognitive bias described by social psychologists David Dunning and Justin Kruger in which people believe they're smarter and more skilled than they actually are. Combine a lack of self-awareness with low cognitive ability and boom: You overestimate your own intelligence and competence. 

Wisdom is knowing that while you might know a lot, there's also a lot you don't know. Wisdom is trying to find out what is right rather than trying to be right. Wisdom is realizing when you're wrong, and backing down graciously.

If you aren't afraid to be wrong, if you aren't afraid to admit you don't have all the answers, if you aren't afraid to say "I think" instead of "I know," then you're likely to be smarter than you think.

3. You like to cuss.

Conventional wisdom says people who swear tend to have limited vocabularies; the F-word is your favorite adjective because you don't have better modifiers at your disposal. 

Turns out conventional wisdom is wrong. According to this research, "The ability to generate taboo language is not an index of overall language poverty."

In short, fluency is fluency. 

So don't assume you're stupid just because you like to use certain cuss words as adjectives and nouns and verbs, sometimes all in the same sentence.

4. You don't get up early.

If you like to get up early, you're in good company: The Wall Street Journal says that 4 a.m. may be the most productive time of the day.

Yet research shows that night owls -- people who feel more alert and productive well after the sun goes down -- are more likely to have higher intelligence, better jobs, and larger incomes than early risers.

But that doesn't mean you have to wake up late to be successful. Or wake up early. 

Waking up at an arbitrary time won't help you succeed. Making a thoughtful decision to wake up at the time that's most productive for you is all that matters.

5. You can delay gratification.

Research shows a definite link between intelligence and self-control. In this study, participants chose between two rewards:

  • Receiving a smaller, immediate financial reward, or
  • Receiving a larger financial reward at a later date. 

People who chose to wait for the larger reward tended to score higher on intelligence tests.

Makes sense: Having the ability to objectively weigh two outcomes and choose the better option is an obvious sign of intelligence.

So if you're willing to exercise a little self-control in order to maximize the fruits of your effort, labor, investments, etc., you may be smarter than you think.

6. You procrastinate.

We all put things off. But few people would assume that putting off something important is a sign of intelligence.

Actually, no. Adam Grant sees procrastination as a key to innovation. As Grant says, "The time Steve Jobs was putting things off and noodling on possibilities was time well spent in letting more divergent ideas come to the table, as opposed to diving right in with the most conventional, the most obvious, the most familiar."

So if you're putting something off just because you don't feel like working on it, that's one thing. But if you're putting something off because you don't feel you've found the best solution, the best path, or the best option, that might be the smartest approach to take.

7. You fail this test.

Here's a really quick test you can take to get an indication of your IQ. Researchers at the University of Rochester created a test to determine the brain's unconscious ability to filter out visual movement. 

First, watch this brief video. The goal is to detect which way the black and white bars drift, whether from left to right or right to left.

The images were presented in different sizes because, generally speaking, it's harder for most people to see movement in larger images. Our brains tend to filter out background movement -- otherwise the world would seem incredibly cluttered and we would be easily distracted. That's why most people do best on the smallest version of the bars; motion perception is optimal in an area roughly the width of your thumb when your hand is extended.

And that's why, when participants observed the smallest image, the people with higher IQ scores were faster at determining the movement of the bars. People with higher IQs tend to make faster perceptual judgments and have quicker reflexes. 

But when participants observed the largest image, those with higher IQs performed worse; the higher a person's IQ, the slower they were at detecting movement.

"From previous research, we expected that all participants would be worse at detecting the movement of large images, but high IQ individuals were much, much worse," said one of the researchers. That means their ability to focus is naturally better: They better filter out background movement to focus on small, nearby moving objects. 

That doesn't mean the test is perfect, but since the task is simple and closely linked to IQ, it may provide clues about what makes a brain more efficient, and therefore more intelligent. (Efficiency always matters.)

"High IQ is associated with motion perception impairments as stimulus size increases," the researchers said. "The results link intelligence and low-level suppression of sensory information. Suppressive processes are a key constraint of both intelligence and perception."

All of which means that if you had a much harder time determining the direction of movement of the bars when the image was large than when it was small, you probably have a high IQ. 

And that means you'll be able to work a lot smarter and harder than the rest of us -- which doesn't require research to know is a great predictor of future success.