Are you secretly a genius??
Well, probably not.
However, there are a number of traits that are scientifically associated with higher levels of intelligence - and they might apply to you.
While most of these points are correlations rather than causal links (i.e. they're linked but you can't say they're due to) they're also worth bearing in mind to throw out the next time people call you an idiot.
1. Difficulty sleeping
If you struggle with imsomnia or have poor sleeping patterns, bear in mind that restlessness at night is associated with higher IQs: the need to sleep per hour decreases as intelligence increases.
Other research suggests that those who prefer to stay up late have higher IQ scores on average, and greater workplace success.
They say Margaret Thatcher only needed four hours sleep a night. Make of that what you will.
2. Monogamy in men
This study demonstrated a correlation between high intelligence and fewer sexual partners for men (although the fewer sexual partners could be a by-product of lifestyle, appearance or general demeanour of the super smart).
But one theory suggests that geniuses deviate from the evolutionary norm. That is to say, that if the average man is designed to be polygamous and pass on their genes to as many offspring as they can, then the brainy men go against the grain.
Also, high levels of testosterone tend to inhibit intelligence while it increases the libido. Less testosterone? Potentially more brain power.
A 2016 study in Language Sciences found that people who swear were generally more verbally fluent overall, and had a better vocabulary - a trait traditionally associated with intelligence.
The study debunked a previously-held assumption that using taboo words demonstrated a lack of better vocabulary to use.
Who knew that swearing could make you sound smarter?
4. Risky decisions
This Finnish study described a correlation between risk-taking behaviour in adolescents, and better decision making skills.
The results also showed that those who made quicker, riskier decisions during simulations had more white brain matter, which is traditionally associated with cognitive function.
Although of course, excessive risk-taking may also be a sign of complete idiocy.
5. Trusting others
According to this study at Oxford University, there is a positive correlation between high IQ and trusting others.
Reasons could be that intelligent people are better at judging character, so they form attachments to more trustworthy people, or that people with a higher IQ are more astute about a situation and can judge the other person's likely behaviour.
The link could also be biological - in terms of evolution, those who trust other humans readily can rely on the support of a social network to survive.
Do you find yourself constantly playing Pinocchio?
Studies have shown that lying requires the brain to reason more efficiently, which means that parts of the brain involved with memory tend to be more developed in people who fib frequently.
7. Social awkwardness or anxiety
Many studies have drawn a correlation link between high intelligence and low social capabilities - although again, this is not a causality, and could be linked to factors such as excessive education or a tendency towards more antisocial intellectual pursuits.
That said, social anxiety has been linked to brainiacs Darwin and physicist Galileo, so...
8. Drinking and drug taking
They say experimenting with controlled substances addles your brain. But a 1970 study showed a direct correlation between intelligence in childhood and illegal drug use in adulthood. Other reports also linked high IQ scores with excess alcohol intake.
That's not to say that drinking or taking drugs will make you more intelligent, but in general, addicts tend to have higher than average IQs.
So if you're drawn to experimentation, the chances are you're more intelligent than you think - or than you seem while intoxicated.
9. Blue eyes
According to this study ('Correlation of eye color on self-paced and reactive motor performance'), those with blue eyes tend to do better at academia and strategic thinking, while brown eyes are linked to quick responses in sporting activities.
In fact, this article from all the way back in 1929 investigated the link between intelligence and pigmentation of hair and eyes in elementary school children.
This study concluded that learning a musical instrument at a young age could have positive effects on brain development, particularly if you start before the age of 7.
In general, the part of the brain that processes information is more developed in a musician than the average.
So if you were forced to learn the recorder as a child, that could actually come in handy.
11. Intelligent parents
If you have brainy parents, the chances are you're smarter than you think. This study showed that an average of 20 to 40 per cent of a child's intelligence is inherited from their parents.
The study excluded environmental factors such as lifestyle, education and upbringing, focussing solely on the DNA.
The results also suggested that while many genes contribute to higher IQs, one gene, FNBP1L, was "significantly associated" with both adult and childhood intelligence.
12. Being left-handed
Left-handedness is traditionally associated with witchcraft, evil and strageness.
Just look at the linguistics- the Latin sinister (left, unlucky), the Anglo-Saxon lyft (weak, broken), the French gauche (awkward, clumsy) vs. right, proper, droit / adroite, the Latin dexter (right, skill)...
But research suggests that left-handed people actually command a higher vocabulary, and have better problem solving skills, due to the differing structure of their brain.
Professor Chris McManus of UCL suggests that the left-handed population has historically produced more overachievers, more musical talent and mathematical giftedness.