Nobody wants to be a number. But there is one number that probably says a lot about you, whether you know it or not: your IQ, or intelligence quotient.(President Donald Trump recentlybragged to Forbes that he would "win" if his IQ test score was compared to that of his Secretary of State, Rex Tillerson.)
IQ is often dismissed as antiquated, misguided, or less important than personality traits. But according to Stuart Ritchie, an intelligence researcher at the University of Edinburgh, there's a massive amount of data showing that it's one of the best predictors of someone's longevity, health, and prosperity. And psychologists have been able to replicate these findings over and over.
(Richie and I go further into why IQ research makes some people uncomfortable in a Q&Ahere.)
In a new book, Intelligence: All that Matters, Ritchie persuasively argues that IQ doesn't necessarily set the limit for what we can do, but it does give us a starting point. And the truth is some people start ahead.
Here are nine facts that help explain IQ and why it matters.
(Most of these charts have been pulled from Intelligence: All that Matters. It's a spry, uncluttered read if you're interested in learning more.)
1) Most people have average intelligence
The first thing to know about IQ is that it is a composite score made up of the results of many different tests of reasoning, memory, acquired knowledge, and mental processing speed. These sub-scores are totaled, and are then compared with those of the rest of the population. A perfectly average score is set at 100.
Note: A full IQ test is an hour-plus, intense process. It needs to be administered by a trained tester, and certain portions are timed. Those free quizzes you see online are not legitimate IQ tests.
Like other variable human traits (height, for example), the range of IQ is on a standard curve bell curve.
Most people you meet are probably average, and a few are extraordinarily smart. Just 2.2 percent have an IQ of 130 or greater.
What's fascinating is that people who score well on one of the tests tend to score well on them all. So your score on a task on how fast you can turn off a blinking light (one component of some intelligence tests) is correlated with your scores on verbal and spatial reasoning.
Psychologists call this overlap of scores the "G," or general intelligence, factor.
"The classic finding — I would say it is the most replicated finding in psychology — is that people who are good at one type of mental task tend to be good at them all," Ritchie says.
Where or how "G" exists in the brain isn't well-understood. But no matter how it arises, the G-factor is real in the sense it can predict outcomes in our lives — how much money you'll make, how productive of a worker you might be, and, most chillingly, how likely you are to die an earlier death.
2) Having a higher IQ protects you from death
This is an uncomfortable one: According to the research, people with high IQs tend to be healthier and live longer than the rest of us. This graph represents a study of 1 million Swedish men. The researchers found a threefold difference in the risk of death between the those with the highest IQs and those with the lowest.
There are a few interrelated reasons why this may be. One is the fact that people with higher IQs tend to make more money than people with lower scores. Money is helpful in maintaining weight, nutrition, and accessing good health care.
It could also be that people with higher IQs are smart enough to avoid accidents and mishaps. There's actually some evidence to support this: Higher-IQ people are less likely to die in traffic accidents.
3) IQ is correlated with career success and wealth, but not necessarily happiness
Like mortality, the association between IQ and career success is positive. People with higher IQs generally make better workers, and they make more money.
But these correlations aren't perfect.
Correlations are measured from -1 to 1. A correlation of 1 would mean that for every incremental increase in IQ, a fixed increase in another variable (like mortality or wealth) would be guaranteed.
Life isn't that pretty. Many of these correlations are less than .5, which means there's plenty of room for individual differences. So, yes, very smart people who are awful at their jobs exist. You're just less likely to come across them.
With all the perks of a high IQ — wealth, health, longevity — you'd think the severely smart would be happier for it. But that's not necessarily the case.
"The correlation between IQ and happiness is usually positive, but also usually smaller than one might expect (and sometimes not statistically significant)," Ritchie says.
Also know that IQ, generally, is not related to the personality factors that can also get us ahead in life. Of the "Big Five" personality traits, the only linked to IQ is openness to experience. "To some degree smarter people will seek out more experiences and think about things more and enjoy considering ideas," Ritchie says.
(IQ often beats personality when it comes to predicting life outcomes: Personality traits, a recent study found, can explain about 4 percent of the variance in test scores for students under age 16. IQ can explain 25 percent, or an even higher proportion, depending on the study.)
4) You're probably stuck with what you got
Studies have found if you're a smart kid, you'll be a smart old person.
This chart shows a Scottish study where a group of 90-year-olds were given an IQ test they previously took at age 11.
Even though intelligence generally declines with age, those who had high IQs as children were most likely to retain their smarts as very old people.
5) Intelligence peaks in your mid- to late 20s, and then slowly declines
I'm 26 years old. And I'm probably as smart as I'll ever be in life.
After your mid-20s, your "crystallized intelligence" — i.e., accumulated knowledge — plateaus, while your "fluid intelligence" — the ability to solve new problems — starts to drop. Your mental quickness takes an even steeper dive.
Ritchie says understanding these age-related intelligence declines is one of the most important reasons for studying the biology of IQ.
"If we know the genes related to intelligence — and we know these genes are related to cognitive decline as well — then we can start to a predict who is going to have the worst cognitive decline, and devote health care medical resources to them," he says.
6) Around half the variance in IQ can be explained by genetics
Studies comparing identical and fraternal twins find about half of IQ can be explained by genetics.
But what's odd is that genetics seems to become more predictive of IQ with age.
That is, twins' genes seem to be less important for IQ when they're children compared with when they're adults. The reason why isn't entirely understood.
Intelligence researchers Robert Plomin and Ian Deary suggest it may be due to what's known as "genetic amplification," a process in which "small genetic differences are magnified as children select, modify and create environments correlated with their genetic propensities," they write in a 2015 literature review.
Consider this: A child with a genetic propensity to be smart may choose to spend more time in a library. A tiny 6-year-old may not be allowed to go to the library by herself. But a 16-year-old can.
The idea is as we age, we grow more in control of our environments. Those environments we create can then "amplify" the potential of our genes.
7) Genes are not the only thing that matters in intelligence
Genetics doesn't seal your destiny when it comes to IQ. About half the variability in IQ is attributed to the environment. Access to nutrition, education, and health care appear to play a big role.
But overall, the environmental determinants of IQ aren't as well understood as the biology.
"In terms of environment, it’s much harder to pin things down," Ritchie says. "People’s lives are really messy, and the environments they are in are messy. There’s a possibility that a lot of the environmental effect on a person’s intelligence is random."
8) Humans are getting smarter
Hurray! Mean IQ scores appear to be increasing between 2 and 3 points per decade.
This phenomenon is know as the Flynn effect, and it is likely the result of increasing quality of childhood nutrition, health care, and education. (In his book, Ritchie explains, it might also be the result of an increased emphasis on knowledge as the engine of our economy, which has encouraged the type of abstract thinking IQ exams test for.)
9) IQ is increasing faster in developing countries
Some of the greatest gains in IQ are happening in the developing world, where increases in childhood nutrition (namely via iodine supplements) and access to health care have made the greatest difference in IQ.
There's actually some evidence that the Flynn effect may be waning in the developed world. "It might well be we are running out of these low-hanging fruits [like standardized education and nutrition] that we know improve IQ," Ritchie says.
One final note: Know that people with higher IQs aren't better at everything. In fact, they're more likely to need glasses to correct for nearsightedness. Nerds!
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85 to 114: Average intelligence. 115 to 129: Above average or bright. 130 to 144: Moderately gifted. 145 to 159: Highly gifted. 160 to 179: Exceptionally gifted.What should your IQ be at 9? ›
|Age of Child||Average IQ|
|8 years old||Between 10 and 30|
|9 years old||Between 10 and 30|
|10 years old||Between 30 and 50|
|11 years old||Between 30 and 50|
85 to 114: Average intelligence. 115 to 129: Above average or bright. 130 to 144: Moderately gifted. 145 to 159: Highly gifted. 160 to 179: Exceptionally gifted.What is the IQ score chart? ›
|IQ Range||IQ Classification|
|120 - 129||Superior|
|110 - 119||High average|
|90 - 109||Average|
|80 - 89||Low average|
Her IQ is probably lower than average, around 90 SD 15. But she has a very entropic personality. Intelligence is ultimately about solving problems.What is Elon Musk's IQ? ›
FAQs (Frequently Asked Questions) When did Elon Musk take an IQ test? The Tesla CEO is estimated to have an IQ score of around 155.Is 120 IQ gifted? ›
To answer this question, 4 categories of gifted students are compared, consisting of above-average intelligent students (IQ between 110–119), mildly gifted students (IQ between 120 – 129), moderately gifted students (IQ between 130 – 144), and highly gifted students (IQ above 144) with respect to underachievement and ...What is the most common IQ number? ›
Most people have an average IQ between 85 and 115. Overall, about 98% of people have a score below 130. Only 2% of the population score above that and are considered above average.Does your IQ increase with age? ›
Does an individual's IQ change with age? An individual's IQ does not change with age. In other words: if you did an IQ test now and then another one in 10 years' time, your IQ score will probably be very similar. This is because IQ is always measured relative to other people your age.What is the IQ number of Einstein? ›
So, what is Albert Einstein's IQ? IQ test experts estimate his IQ was somewhere between 160 and 180, which is quite high. Some people estimate his IQ was just over 200, hovering around 205. However, 160-180 is the more commonly estimated range.
Professor Hawking, the theoretical physicist known for his work on black holes, is said to have had an IQ of 160.Can you increase IQ? ›
Although science is on the fence about whether you can raise your IQ or not, research does seem to suggest that it's possible to raise your intelligence through certain brain-training activities. Training your memory, executive control, and visuospatial reasoning can help to boost your intelligence levels.What is a typical IQ score by age? ›
|Age Range||Average IQ Score|
|20 to 24-year-olds||99|
|24 to 34-year-olds||97|
|35 to 44-year-olds||101|
|45 to 54-year-olds||106|
Kanye says he scored a 133 on Mensa IQ test, compares his brain to women's bodies.Does Lady Gaga have a high IQ? ›
2 Lady Gaga's IQ Is 166
One thing that many may not know is that gaga actually has an impressively high IQ of 166 which means that she falls into the exceptionally gifted category — just like Ashton Kutcher, Quentin Tarantino, and Matt Damon.
The average IQ varies from country to country, with the US standing at 98. Anything above 130 is high. Here are some of the glimpses of genius that attest to Bill Gates' high IQ, even to the point of being a 160 score.Does Ashton Kutcher have a high IQ? ›
But little do fans of That '70s Show and Dude, Where's My Car know that Kutcher bears no similarities to some of his former on-screen characters. The-now 44-year-old has an estimated IQ of 160, evident in his humanitarian work (he's assisted with the plight of child trafficking) and investment work.
Taylor Alison Swift is an American singer songwriter. According to some acclaimed websites, she is said to have an IQ of 160. As a matter of fact, she is listed in the Guinness Book of World Records as the youngest singer ever to sign at age 11.Is Snoop Dogg's IQ really 147? ›
Conversation. : FACTS: According to IMDB, Snoop Dogg's IQ score is 147, which is considered to be extremely high and that of a gifted genius.What is the average IQ in the United States? ›
Average IQ in USA
The American average IQ is 98, according to the latest data from 2022. Historically, the average IQ score in the US has been rising steadily, with an average increase of about 3 points per decade. This increase is attributed to factors such as improved education, healthcare, and nutrition.
Like most aspects of human behavior and cognition, intelligence is a complex trait that is influenced by both genetic and environmental factors.What is the average IQ of a PhD? ›
Originally Answered: What is the average IQ of PHds? It depends on the field. Generally above 120, similar to law and medicine. For physics and math, some estimates are around 145.What is the average IQ of a nurse? ›
Pharmacists average around 120 and nurses in the high 110's. You can find a link to the full list with more professions in the description.What is the most attractive IQ score? ›
On average, the 90th percentile of intelligence (IQ≈120) was rated to be the most sexually attractive and the most desirable in a long-term partner. However, 8.1% and 1.3% of the sample scored above 4.0 and 4.5, respectively, on the SapioQ (theoretical range: 1 to 5), which had respectable psychometric properties.What is the average IQ of a woman? ›
IQ scores between 90 and 109 indicate a normal range or average intelligence. Individual adults usually score somewhere in between the 70-130 range, with 100 being the theoretical average.What are signs of a genius? ›
Ability to learn new topics quickly. Ability to process new and complex information rapidly. Desire to explore specific topics in great depth. Insatiable curiosity, often demonstrated by many questions.At what age is your IQ at its highest? ›
Scientists have long known that our ability to think quickly and recall information, also known as fluid intelligence, peaks around age 20 and then begins a slow decline.At what age is a person's IQ the highest? ›
IQ peaks at around 20-years-old and later effort will not improve it much beyond this point, research finds. The complexity of people's jobs, higher education, socialising and reading all probably have little effect on peak cognitive ability.What ethnicity has the highest IQ scores? ›
In the US, individuals identifying themselves as Asian generally tend to score higher on IQ tests than Caucasians, who tend to score higher than Hispanics, who tend to score higher than African Americans.What is the IQ of a smart person? ›
An IQ score over 140 indicates that you're a genius or nearly a genius, while 120 - 140 is classed as "very superior intelligence". 110 - 119 is "superior intelligence", while 90 - 109 is "normal or average intelligence".
Smartest Person in the World in 2023: Smartest Person Alive with highest IQ. Marilyn Vos Savant may well be the smartest person alive today. With an IQ of 228, she holds the highest IQ in the world by the Guinness World Records since 1990.Who had 1,000 IQ? ›
Marilyn vos Savant (/ˌvɒs səˈvɑːnt/; born Marilyn Mach; August 11, 1946) is an American magazine columnist who has the highest recorded intelligence quotient (IQ) in the Guinness Book of Records, a competitive category the publication has since retired.What is the lowest IQ ever recorded? ›
What Is the Lowest IQ Ever? There's no record of the lowest IQ ever. However, the lowest IQ score possible is zero.How to check your IQ? ›
The IQ score can be calculated with the formula of IQ = (intelligence age/actual age) x100. Here is a short list of the most common IQ tests (intelligence quotient test), other than MentalUP's online IQ test that you or your children may want to take: Stanford-Binet (SB-V) Wechsler Adult Intelligence Scale (WAIS-IV)Does reading increase IQ? ›
It increases intelligence.
Exposure to vocabulary through reading (particularly reading children's books) not only leads to higher score on reading tests, but also higher scores on general tests of intelligence for children. Plus, stronger early reading skills may mean higher intelligence later in life.
The reality is that IQ results are usually fairly accurate. The psychologist conducting the test ensures this by making sure they don't just look at the test score in isolation. If they're working with a child, for example, they might take into account other factors.Does chess improve IQ? ›
Chess has been proven to increase your IQ, improve memory function, help develop higher levels of creativity, simultaneously exercise both sides of the brain, help prevent Alzheimer's and dementia, and increase a child's problem solving skills.What is the average IQ score of a genius? ›
Notably, the average IQ score falls between 85 and 115. A score above 140, meanwhile, is considered to be genius level.How rare is an IQ of 130? ›
Most people you meet are probably average, and a few are extraordinarily smart. Just 2.2 percent have an IQ of 130 or greater. What's fascinating is that people who score well on one of the tests tend to score well on them all.Is an IQ of 135 good for a 13 year old? ›
Scores of 90-109 are Average. Scores of 110-119 are High Average. An IQ of 125 is considered by many schools to be “gifted.” Scores of 120-129 are Superior. And scores above 130 are Very Superior.
|Rank||College||Estimated IQ from SAT Score|
His IQ was definietly higher than average. I've read somewhere that his IQ was between 150–160 i m not sure about the exact score though.How much IQ does Justin Bieber have? ›
probably between 125 and 140 … and most Ph. D physicists are at 135.Is Sylvester Stallone intelligent? ›
Not the first person you would associate with the word genius, Sylvester Stallone is considered one of the smartest guys in Hollywood and, like his equally brawny mate Dolph, has a Mensa IQ score of 160.What is Emma Watson's IQ? ›
Emma watson: iq of 138 | MARCA English.What was the IQ of Isaac Newton? ›
Isaac Newton is estimated to have an IQ Level of 190.What was Bob Dylan's IQ? ›
Bob Dylan, famous folk and rock musician had an IQ test score of 106.What is a low IQ for a 9 year old? ›
A normal IQ score is around 100. Children with ID have a low IQ score–most score between 70 and 55 or lower.Is 125 IQ good for a 9 year old? ›
Scores of 90-109 are Average. Scores of 110-119 are High Average. An IQ of 125 is considered by many schools to be “gifted.” Scores of 120-129 are Superior. And scores above 130 are Very Superior.How do I know my 9 year olds IQ? ›
The Intelligent Quotient is obtained by dividing the mental age (MA) by the chronological age (CA) so that children of different chronological age can be compared. To remove the decimal point, the result is multiplied by 100. Therefore, IQ = MA/CA X 100.
A young Mexico City native is spectacularly shattering widespread misconceptions about individuals with developmental disorders by proving her incredible intellectual capabilities at just 9 years of age. Adhara Pérez Sánchez has already made a name for herself in academic circles with an impressive IQ of 162.At what IQ is a child considered a genius? ›
The first genius IQ score was around 140. That's about one in every 250 people. But one leading researcher in the 1940s suggested that a genius should have an IQ over 180.Does IQ change with age? ›
Does an individual's IQ change with age? An individual's IQ does not change with age. In other words: if you did an IQ test now and then another one in 10 years' time, your IQ score will probably be very similar. This is because IQ is always measured relative to other people your age.What is a good IQ score by age? ›
|Age Range||Average IQ Score|
|20 to 24-year-olds||99|
|24 to 34-year-olds||97|
|35 to 44-year-olds||101|
|45 to 54-year-olds||106|
Talk to them and read to them.
Playing simple teaching games along the way, for instance asking them to name or count objects, boosts their intelligence even more. "You can raise your child's IQ by six points by simply doing this over a few years when they are young," Roche writes. Start as early as you can, he adds.
Although science is on the fence about whether you can raise your IQ or not, research does seem to suggest that it's possible to raise your intelligence through certain brain-training activities. Training your memory, executive control, and visuospatial reasoning can help to boost your intelligence levels.What is the best IQ test for ADHD? ›
The Weschler Intelligence Scale for Children (WISC), originally developed in 1949, is probably the most common intelligence test currently in use.Can an 8 year old have an IQ of 130? ›
An 8-year-old child with a mental age of under 6 will need some help doing what most other 8-year-olds can do. Now consider the 8-year-old with an IQ of 130. It should be just as clear that a child with that score needs special accommodations. He has the mental capacity of most 10-year-olds.What autistic child has the highest IQ? ›
The genius child, Adhara Pérez Sánchez, has an IQ that beats Albert Einstein — whose IQ is estimated to be around 160. Adhara finished her High School education at the very young age of seven. Mirror UK reports that the genius girl will soon be awarded a masters and is currently working with the Mexican Space Agency.Which Mexican girl has an IQ higher than Einstein? ›
Adhara Pérez Sánchez (born 2011) is a Mexican space science prodigy and public speaker. Having been diagnosed with Asperger syndrome at age 3, she is currently studying industrial engineering in mathematics at the Universidad Tecnológica de México.
Other people with some of the highest IQs are Sho Yano, who had an estimated IQ of around 200 at 10 years old, and Adragon De Mello, who had a projected IQ of 400 and graduated from the University of California, Santa Cruz at 11 years old, according to Reader's Digest.