IQ Test

What is IQ

Intelligence Quotient or IQ is a method of measuring the intelligence of a person. The IQ scale begins at zero and is open-ended, with the highest IQ recorded being around 300. The average IQ is a score of 100, and most tests will not reliably give an indication of any score above 170 – this is above genius level and more thorough investigation is needed for intelligence rated so highly.

IQ test

What does an IQ test measure?

Simply, intelligence. Intelligence and IQ are not the same as “being clever”, but more related to problem-solving and the use of logic. Therefore, the question that some people may ask, “What IQ does a dog have?” is nonsensical. The intelligence of a dog cannot be quantified in the same scale as a human.

Are IQ tests fair

Certain factors can make IQ tests fair. As a human is not comparable to an animal, learned abilities and cultural differences should not affect the outcome of an IQ test. In the simplest terms, if an IQ test written in English was presented to an English speaker, they might score 120. If the same test was written in French, the English speaker may only score 10. If they learned to read French, their score would go up, but it would not represent their intelligence.

Therefore, IQ tests can be made fair by the way they are designed. If they use abstract imagery and are presented in a limited number of colors (to prevent issues with colorblindness) the most accurate results will be discovered.

History of IQ Tests

Humans have always been interested in measuring their own qualities and those of others, but it took until 1904 for a way to measure intelligence to be established. British psychologist Charles Spearman created the “g factor”, a measure of general intelligence, in that year.

History of IQ test

The term “IQ” was coined by another psychologist, William Stern, taking a person’s developmental age and expressing it as a percentage of their chronological age. The method used these days is slightly different, but the terminology remains.

By the 1940s, different types of intelligence were recognized, including fluid intelligence and crystallized intelligence, terms created by psychologist Raymond Cattell. IQ test focus on fluid intelligence, the problem-solving, analytical, pattern-identifying kind of intelligence. You can find out more about this on our What is Intelligence? page.

Of course, even before modern-style IQ testing became common, there were attempts to classify people based on their intelligence. One of the more successful was the Binet-Simon test, created by Alfred Binet and Théodore Simon in 1905, and focused on the verbal abilities of the subject.

Robert Yerkes assisted the US Army during World War 1 with both written tests and non-verbal tests that gave results based on performance – one of the first attempts to separate intelligence from having knowledge.

David Wechsler created a test in 1939 that included multiple subtests and gave a more thorough evaluation than previous single tests. By the 1960s, the Wechsler test was the most popular IQ test in the US and remains that way until today.

Further research and developments have led to the belief in multiple types of intelligence, including visual and auditory processing abilities as well as reasoning.

Online IQ Tests

Many online IQ tests are now based on the research of David Wechsler due to the comprehensive analysis the test can provide.

IQ Test results

The ultimate aim of any IQ test is to give you an indication of your intelligence. IQ test results may be presented as a number (your estimated IQ), the range in which your IQ is (e.g. 100-110), a name for the range (e.g. average intelligence, genius, etc.), or an indication of the percentage of questions you succeeded in answering correctly.

IQ Test for Kids

There is some debate about when to IQ test a child and many IQ tests will not provide valid results for children under 16. While IQ tests for kids are available and can be found online, they may not provide results as reliable as the tests that are taken by adults.

IQ Test for Kids

There is an indication that the IQ of children aged 5-7 correlates less well with the IQ of the same people at 17-18 than the correlation with ages 11-13 and 17-18. What this means, in simple terms, is that intelligence and problem-solving abilities develop as a child grows, and the younger the child is, the less likely they are to be able to successfully complete an IQ test.

Free IQ Tests

Can an IQ test be reliable, especially if it is provided for free? Yes, it certainly can. As noted above, IQ tests for those under 16 should be taken with a pinch of salt, but by age 16 properly constructed IQ tests can provide IQ test scores that are extremely close to offline tests that are conducted under medical supervision.

Ensuring that the test is fair cross-culturally is important as it prevents the use of prior knowledge to complete the test – an IQ test is a test of intelligence, not of knowledge. Anyone can learn facts from a book, but this does not show intelligence.

What is an average IQ?

The average IQ in any population is always 100 by design. As more people take IQ tests, the average score in the tests may change, and so the related IQ of individuals will be modified to adapt.

How does IQ test scoring work?

As an example, if three people take an IQ test and score 50%, 75%, and 100%, the average score is 75%. Therefore, anyone who scores 75% will have an IQ of 100.

However, should another ten people take the test and score 50% or below, the average IQ test scores will be pulled closer to 50% - say 57%. The next person who takes the test scores 60% and will be noted to have an IQ of above 100.

This is because the average score is now 57% which makes 57% the score needed to be awarded with an IQ of 100. Because it is an average, the greater number of people to have taken the test provides the most accurate result as the average will have smoothed out due to the number of reference points.

What are average IQ ranges?

On this basis, an IQ of between 90 and 109 is considered to be normal. Below 70 can be considered mild mental retardation, while 130 to 139 is considered gifted.

140 and above is genius level, and only a very small proportion of the population fit in this category – similarly, only a small percentage have an IQ of 50 or lower, which is why the averaging works so well.

You can find out more on our Definition of IQ page.

Which IQ test should I take?

There are many tests online, but clearly our recommendation would be to take the Worldwide IQ Test. It has been designed by an experienced doctor to be used by those 16 and above and is culturally fair. Additionally, it avoids problems associated with color-blindness, as the ability to distinguish colors is also not a factor in determining intelligence.

Which IQ test should I take?

Many people have heard of the Mensa IQ test and want to join Mensa itself. Our test cannot be used to allow entry to Mensa but will give a strong indication of whether you could pass the Mensa test.

Mensa IQ Test

The Mensa IQ test is renowned as one of the toughest tests to pass. Your IQ can be derived from the results, and success usually requires a IQ test scores of over 140.

There’s more about the Mensa test in our Mensa IQ Test article.

Mensa IQ test Limit

The actual criteria to pass the test is that you must score higher than 98% of the population, so only 2 out of every 100 people are likely to pass the test. You cannot repeatedly take the test, and a second sitting is often uncommon, which make Mensa a very exclusive club.

Find out more in our Mensa IQ Test Limit article.

How to Prepare for Mensa test

Preparation is the key to many things and passing the Mensa test is no exception. Eating a healthy diet and looking after yourself may seem like something that improves your physical wellbeing rather than your mental state, but the two go hand in hand.

The best way to prepare is to take a real IQ test, possibly multiple times, before attempting the Mensa test. This will help you to understand the format of the questions, how it feels to complete an IQ test, and give you an idea of your current IQ. If you are way below 140, you’ll need to put some more practice in.

Can my IQ change?

Yes, and it may not be anything to do with you. While practice and training can improve your intelligence, your IQ is rated against the average of all other people who have taken the test. If many people obtain low scores, the average IQ will become lower, but will still be represented by 100. This means your IQ score will increase in relation to the general population.

Can my IQ change?

But this should not affect the way in which you approach preparing for a Mensa test. The more practice and brain training you can complete before taking the test, the better. You can find out more detail about this approach by reading the How to Practice for Mensa Test article.

Flynn Effect

Since the creation of the IQ system, results in IQ tests have improved over the course of time. Every so often, the average is recalculated, and the score required in a test to achieve an IQ of 100 has increased.

If the average had never been recalculated, IQ scores would have increased by approximately 3 points per decade since around 1920. After much research, it seems that this trend is caused by environmental factors rather than genetics.

This increase in IQ over time has been called The Flynn Effect after James R Flynn, author of the book The Bell Curve where the phenomenon was first noted.

A slowing or even reversal of the Flynn Effect has been seen in the last few decades in some Western countries, but again the phenomenon appears to be environmental.

3 Geniuses with highest IQ

There have been many geniuses throughout the history of humankind, some more well-known than others. Scientists often lead the way, with names like Albert Einstein and Sir Isaac Newton springing to mind, but there are geniuses in many fields. Here are 3 other geniuses you may have heard of.

Leonardo Da Vinci

Leonardo Da Vinci was born in 1452 in present-day Italy. Talented and full of ideas, as well as a curiosity to discover more about everything he came into contact with, it has been estimated that Leonardo’s IQ was in the region of 220.

Highest IQ Leonardo da Vinci

From works of art including the Mona Lisa and The Last Supper, to drawings of human anatomy, and designs for robots and powered weapons of war, along with parachutes and bridges. Many of his designs are common or expected items in modern times but remember – he had the idea over 500 years ago!

Stephen Hawking

Presumed to have an IQ score of over 160, it is unknown if Stephen Hawking ever took an IQ test, and didn’t take too kindly to those who boasted about their results. However, before he died in March 2018, Stephen Hawking provided tremendous evidence that his mind was capable of analyzing and solving problems that were universal in size and nature.

Stephen Hawking IQ

With a body that failed him due to the effects of ALS, on of Hawking’s best-known discoveries was in relation to the radiation emitted by black holes, which was previously unknown. Further research into theoretical and quantum physics provided the groundwork for a large proportion of what we know about the universe today, possibly even surpassing Einstein’s contribution to theoretical physics.

Garry Kasparov

Said to have an IQ of 190, Garry Kasparov is possibly most well-known for being a former world chess champion. His amazing analytical mind made him a formidable opponent for any chess player. He became world number 1 in 1984, at the time the youngest ever player to achieve this.

Garry Gasparov IQ

He has since become a political activist and now puts his problem-solving skills towards resolving human rights issues.

3 Things You Should Know About IQ Test

1 – Your IQ doesn’t represent your worth

Your ability to do your job, be a parent, or be a friend is not reflected by your IQ. Your IQ is a measure of how you perform in logical puzzles and problem-solving activities against the rest of the population, a measure of your intelligence – and that’s all.

2 – You can improve your results on an IQ test

If you’ve taken an IQ test and were disappointed with the result, prepare for you next one in a determined manner. Eat well, sleep well, take some practice tests. Everything you do to improve your intelligence will help increase your score on an IQ test.

3 – IQ Test questions are meant to be difficult

Just because you can’t answer one or two (or several) of the questions on an IQ test, it doesn’t mean the IQ test is too hard. It’s designed to be difficult to see how well you perform – if all the questions were easy, everybody would be a genius!

3 Things You Should Know About IQ Test

Why should you take IQ test?

Everybody wants to improve themselves and their position in life. Knowing what your IQ is to begin with gives you a starting point to work from…and more importantly, taking IQ tests can be fun! So what are you waiting for? Take your first IQ test right now!

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