Average IQ score by age—how do you stack up?

In an era where exceptionalism is an expectation, we make a case for the average. In this instance, it’s for the average IQ score by age.

Where do you stand on the spectrum? Let’s find out.

What is IQ?

IQ stands for “intelligence quotient”—based on the German term “intelligenzquotient“—and was coined by psychologist William Stern in 1912. It’s a numerical score that “indicates how far above, or how far below, his/her peer group an individual stands in mental ability,” as described by the largest and oldest high IQ society in the world, Mensa International.

Very left-brain-based, it’s essentially a measurement of your ability to apply logical reasoning to solve problems. Mensa International explains that in adults, IQ is not really a quotient at all. Instead, it’s “an indication of how well one performs on mental tests compared to others.”

But that doesn’t mean your IQ is “better” than that of a three-year-old. Or that of a centenarian, for that matter. Your IQ measures against your age, too.

How are IQ scores calculated?

The two-letter term, IQ, was initially measured as a ratio of mental age to chronological age multiplied by 100.

For example, if you’re ten years old with a mental age of ten, your IQ would be 100. If your mental age is greater than your chronological age (let’s say, 15 instead of 10), then your IQ would be 150. Similarly, if your mental age was lower than your chronological age, then your IQ would be that, multiplied by 100.

Index scales of modern IQ tests

Nowadays, IQ tests measure an adult’s intelligence on these index scales:

• Verbal reasoning measures how a person processes words, assesses them, and applies them—concept formation, comprehension, and expression. The questions given assess how words are received, storing and recalling information, reasoning or solving verbal problems, and communicating knowledge. 
• Perceptual reasoning measures the ability to assess visual details and identify their spatial relationships or patterns. The questions on this subtest typically ask to construct geometric designs from a model, identify distinguishing details between similar images, and so on.
• Working memory measures the ability to register, maintain, recall, and manipulate information—both visual and auditory—in a short period of time. The person is given a series of information and tested on how well they recall the information.
• Processing speed measures how quickly new information is processed. Specific tasks are given to be completed in a certain amount of time.

Your points gained on these subtests are then combined to form an overall IQ score.

Mensa International explains that when the concept of IQ was extended, one major development in its testing was the creation of group tests. Prior to this, people were tested individually by qualified psychologists. “The first group test was created for the US Army,” they point out. “They soon spread to schools, workplaces, and beyond, becoming one of psychology’s greatest popular successes and remain so to this day.”

What’s the normal IQ range?

There are several kinds of tests to calculate your IQ. The most trusted and widely used is the Wechsler Adult Intelligence Scale (WAIS)—its fourth edition has the following score range:

So in a nutshell, when you score higher, the higher your “intelligence.” And if you’re curious as to where you stand on this intelligence scale, you can take the IQ test to find out.

What is the average IQ score by age?

There isn’t any actual data on the average IQ score by age. However, there’s some information about age groups, and here are the scores that denote “normal” or “average” intelligence.

It’s important to note that these scores by age should be taken with a pinch of salt. Given that modern IQ tests, like WAIS-IV, consider a person’s age, it’s applicable to those 16 years old and older.

The average IQ scores follow the bell curve, which you can find above. For those below that age, there’s a WAIS-V test that’s available.

What’s the difference? For the fifth edition, there’s an extra index scale.

While WAIS-IV looks at verbal reasoning, perceptual reasoning, working memory, and processing speed, WAIS-V adds fluid reasoning to the list. This measures a person’s ability to identify relationships among visual objects by completing a series of visual patterns. But essentially, the scoring system follows the same bell curve.

What is the average American IQ?

The average American IQ is 97.43, according to the World Population Review of 2022. This ranks them in 29th place after Belgium and before Norway.

The thing is, this seems to be quite far from their standings in 2017, where they were ranked number one in the Top 10 Countries with the Highest Intelligence Capital Index list.

As for the country with the highest average IQ scores in the world? According to a 2019 study, that title belongs to the Japanese, with Taiwanese and Singaporeans close behind. And they will maintain that status in 2023.

What’s the average IQ?

The average IQ score for any age group is 100—the center of the “normal” range. Most IQ scores fall somewhere around this number. And as the scores move away from the normal range (100), there are fewer and fewer scores. This is known as the standard deviation.

You’re actually deemed to be within the “normal” IQ range if you score anywhere between 85 and 115 on your test. 

Anything over that would be considered “exceptional,” like Marilyn vos Savant, who has the highest IQ score of 228 at the age of ten, according to the Guinness Book of Records.

Likewise, anything under 100 would be regarded as “intellectually disabled.” Even for the lowest IQ, that’s harsh.

Why high/low IQs do NOT measure intelligence

Wherever you fall on the IQ score spectrum, here’s the fact of life: there’s really no such thing as a good or bad IQ score.

Why? Simply, your IQ is such a narrow measure of specific cognitive abilities. And frankly, it does a poor job of reflecting the vast world of your mental capacities and intellectual strengths as a unique individual. It also doesn’t take into account the different types of learning styles.

New research in this field reveals that we may actually possess up to nine different types of intelligence. And you can develop each of them by learning to improve your brain functions.

So what field of intelligence would you genuinely like to be sharper in? What’s something completely new you would like to learn? What cognitive abilities would serve you in living your best life? These are the questions that actually count.

Unleash your superbrain

Whether you’d like to learn a new language or instrument, learn how to read faster, remember people’s names forever, or just boost your memory in general, it’s never too late. The truth is, your brain is a muscle, and nothing is stopping you from training it to be stronger.

That’s right—your “intelligence” isn’t set, and it can improve tenfold with the right coach, someone like Jim Kwik, author of Mindvalley’s Superbrain Quest. With his guidance, you’ll have the tools and techniques to awaken your superhuman memory, focus, and learning speed. It’s time to unleash your super brain.