What Is the Average IQ?

The average IQ is 100 - by design

IQ tests are "normed": before a test is published, it is given to a large sample of people chosen to represent the population. Their results are then scaled so that the middle score becomes 100 and the spread (standard deviation) becomes 15. So the average IQ is 100 not because of some law of nature, but because that is how the scale is built.

• About 50% of people score between 90 and 110.
• About 68% score between 85 and 115.
• About 95% score between 70 and 130.

What is a good IQ score?

Any score from 90 to 109 is average. 110-119 is high average, 120-129 is superior, and 130+ is very superior - roughly the top 2%. See the full IQ scale and score chart.

Does the average IQ change with age?

No - and yes. Your IQ is always compared with people your own age, so the average stays 100 at every age. But the abilities underneath change: fluid reasoning (solving new problems) tends to peak in early adulthood and slowly declines, while crystallised intelligence (vocabulary and knowledge) often keeps growing well into your 60s.

The Flynn effect: are we getting smarter?

The political scientist James Flynn noticed that raw scores on IQ tests rose by about 3 points per decade through much of the 20th century in many countries - which is why tests have to be re-normed every so often. Better nutrition, schooling and more abstract everyday thinking are the usual explanations. In some countries, such as Norway and Denmark, the rise has slowed or even reversed since the 1990s.

Can you raise your IQ?

Education seems to help: a large 2018 analysis by Ritchie and Tucker-Drob found that each extra year of schooling was linked to roughly 1 to 5 more IQ points. "Brain training" apps, on the other hand, mostly make you better at the games themselves rather than raising general intelligence. Sleep, exercise, reading and learning genuinely new skills are the best-supported ways to keep your mind sharp.

How does an online test compare?

A clinical IQ test is given one-to-one by a psychologist and takes over an hour. A good online test uses the same kinds of questions - patterns, numbers, words, logic and shapes - and the same scoring scale, which makes it a useful and fun estimate. It is not a diagnosis.