IQ-Brain Blog

Multiple intelligence test

Multiple intelligence test factors
Spearman’s G can be broken down into multiple intelligence test factors

The intelligence quotient or IQ is a score which attempts to describe someone’s intellectual or cognitive ability. G-factor analysis is the psychometric evaluation of cognitive abilities. More specifically, General Intelligence or Spearman’s G (G), is believed to be a leading indicator which explains 40-50% of the variability of test takers’ performance on individual cognitive tasks. In other words, the level of your general intelligence (usually represented by a global IQ score) will correlate strongly to your performance on individual cognitive tasks.

Thurstone (1938) was an opponent of G and expanded the narrow definition of intelligence to encompass 7 primary types of mental abilities, which could be measure in multiple intelligence tests:

  1. Verbal comprehension
  2. Word fluency
  3. Number
  4. Spatial ability
  5. Associative memory
  6. Perceptual speed
  7. Reasoning or Induction

Raymond Cattell was Charles Spearman’s doctoral student in the 1920s. Cattell also believed that intelligence could be broken down into components . Cattell would go on to assert that general intelligence (g) could be broken down into (1) fluid intelligence – Gf -or raw processing brain power; and (2) crystallized intelligence – Gc -which is associated with verbal skills and usually correlated with formal education.

Cattell’s work would turn out to be just a first step. John Horn was Cattell’s doctoral student and just as Cattell expanded his PhD mentor’s theory on intelligence, so did Horn.

Multiple intelligence test – according to John Horn

Horn never really fully bought into Gf Gc theory and he quickly identified four abilities in addition to Gf and Gc (1965, 1968).

Gsm = short-term acquisition and retrieval

Glr = long-term acquisition and retrieval

Gv = visual processing

Gs = speed of processing

To this day, most reputable IQ tests will are akin to multiple intelligence tests and will measure one or more of the above cognitive abilities.

At, we have a developed a fluid intelligence test which is really a multiple intelligence test in that it also measured Gsm, Gv and Gv. The IQ score that you will see on our tests will reflect your composite performance on test questions which encapsulate short term memory, visual processing and processing speed. TEST YOUR IQ HERE.


Average IQ

Normal IQ
Average IQ is typically 100

Average IQ is a relative concept. IQ tests as we know them today originated in France in the 1890s when Alfred Binet was asked by Parisian education ministers to create a process of evaluating the intellectual abilities of children. The aim of the education ministers was to identify children that were not clever and to remove these children from the classroom as it was thought that their inclusion would slow down and hinder the development and academic progress of the rest of the group.

So at its origins, IQ testing was used to weed out children with lower-than-average intelligence quotients, rather than to identify giftedness. The term IQ or intelligence quotient was truly descriptive of the process by which intelligence was ascertained. When Binet first developed his measurement technique, he set out to establish a scale of mental abilities (MAs) for children of different age groups. So in effect, he used tests of verbal ability to determine, on average, the proficiency level for children of each age group. Once it became clear of the range of performance outcomes that could be expected for children of a given age, he then compared this to the actual calendar age (CA) of the test taker. More specifically, IQ was calculated as MA/CA x 100. So if the child’s MA was equal than his or her CA, then that child have been considered to have an average IQ because MA=CA.  Taking an example, a six year old with an MA of 6 would have an IQ of MA/CA x 100 = 6/6 x 100 = 100. This is exactly where the concept of average IQ being 100. In other words, average IQ means that your intellectual ability is commensurate to your age.

Average IQ – the normal distribution

In the 1930s, Weschler introduced the concept of standard score which would eventually replace the MA/CA IQ measure. The benefit of using standard scores included that they were much more robust than the MA/CA technique which would break down for older test takers. It would then be established that IQ followed a normal distribution, with a mean (or average IQ) of 100 and a standard deviation corresponding to the observed distribution of variability of test responses by the individual test takers. With the mean and standard deviation known, then statisticians were able to compute test statistics and determine how individual test scores ranked relative to the average.

Assuming a standard deviation of 16 points, we know that c.68% of the population will have an IQ of between 84 and 116 points, and that 98% of the population will have an IQ which is two standard deviations from the mean, namely between 68 and 132. An IQ of 100 within a given country is assumed to the the average IQ level. However, clinical psychologists consider an IQ ranging between 90 and 109 to be average IQ, or average intellectual ability. Based on the statistical properties of the normal distribution, we know that roughly 47% of the population have an IQ within the average range.

To test your IQ, you can take our fluid intelligence IQ test HERE.

Free IQ test

Free IQ tests vary in quality
Free IQ tests vary in quality – we provide a link to some of the better ones

There are a very large number of IQ testing resources online.  Unfortunately, very few of the online IQ tests are any good. The issue with the vast majority of online IQ tests is that they tend to over estimate test takers’ IQ. So test takers will end up thinking that they are smarter than they actually are. Although this may be good for the ego, it does not provide the test taker with a real sense of his or her cognitive strengths and weaknesses. More importantly, an IQ test is meant to give you an assessment of where you stand relative to a given population. The concept of whether or not someone is smart is a relative question. And the answer to the question lies in comparing the test taker’s IQ to that of the average person in his or her home country. So what is the point of being told by a free IQ test that you have an IQ of 140+ (genius level), when in fact your true IQ may really be around 115.

Free IQ test – you pay for what you get

Although most free IQ tests are neither very accurate or any good, some of them are, but you really have to look for them. The following site has compiled a list of free IQ tests and paid-for IQ tests that are amongst the best on the web. Click here to see the list.

At, we aim to provide the most accurate culture-fair IQ testing on the free. We do not offer a free IQ test, although you can start our test 1 for free. The price for obtaining a result is modest in comparison to several of our competitors, More importantly, we aim to provide you with a realistic estimate of your fluid intelligence for as little as $9.00 (or $15 for three tests). Professional psychologists can charge up to $1,000 for a professional assessment, and the academic literature has shown that clinical psychologists’ scoring can be highly subjective (variances of 8-10 IQ points in the scoring have been shown for the same test result!). Our IQ tests use standard scoring methodology which eliminates this problem. Test your IQ here.


National IQ test

National IQ tests
National IQ tests lose relevance in a globalized context

What is the importance of a national IQ test? Let’s first start by defining what IQ is. IQ, or the Intelligence Quotient, is a score which attempts to quantity one’s intellectual or cognitive abilities. At its origins, IQ was calculated as the ratio of Mental Age (MA) divided by the person’s Chronological Age (CA). Although this equation was beautiful in its simplicity (determining someone’s age is very easy!), establishing a robust expectation of MA should look like for people of different age groups was the hard part. Establishing a robust Mental Age (MA) scale would become an ipsative benchmarking process in which the test developer identified mean scores on a series of mental tasks that could be expected to be achieved by people of the same age. Naturally, you would expect eight year olds to be able to achieve more than say, five year-olds on the same mental tasks. Once test developers established the MA benchmark for every age group, calculating IQ was easy as you divided an individual’s MA by that person’s Chronological Age (CA). If the test taker exhibited advanced mental capabilities for his or her age (i.e. performance beyond their years), then that test taker’s IQ ratio would be greater than 1.  Multiplying this score by 100 would yield an IQ score where 100 was the average (corresponding to your mental ability being consistent for a person of your age). For example, an eight year old (CA=8) that is able to perform mental tasks corresponding to the average 10 year old (MA=10), would have an IQ of MA/CA = 10 / 8 = 1.25 x 100 = 125 IQ.

When this initial testing methodology was first developed in the late 1800s, the scale of MAs that were established by Frenchman Binet would have reflected a national MA scale relating Parisian children which is akin to saying that his IQ scale was a Parisian IQ test rather than a French National IQ test (that is, it is now well-observed in the academic literature that people living in urban centers will, on average, have higher IQs). But the real problem with the MA/CA technique is that MA reaches full adult maturity when people reach the age of 16, and this creates problems for older adults on the same IQ scale. A 40 year old could well have an MA of 16, which would imply an IQ of 40/16 = 2.5 x 100 = 250. Clearly, this would not make any sense.

IQ tests and national IQ tests have now come a long way and the calculation of IQ scores is no longer dependent on the MA/CA equation. The calculation of IQ has changed, but the principles underpinning IQ scales have not changed fundamentally. That is, IQ scores are now calculated using standard scores (think normal distribution which can be described using mean and standard deviation) which eliminate the problem highlighted above for older adults. But the process employed by test developers of establishing average performance for various age groups remains largely the same. That is, as in the case of establishing the MA scale, test developers need to be able to establish the mean performance of a group of individuals of a certain age on a given test. To do this properly, you need a truly representative random sample of people of the country – for each age group- for which you are trying to establish a national IQ test scale.

National IQ tests in a global world?

So why the emphasis on a national IQ test? Taking a National IQ tests implies that you are being benchmarked against people of your home country. Why not other countries? Well, the literature has now clearly established that mean IQ scores and average cognitive abilities vary by country. The differences can be substantial. For instance, Americans and Canadians may well achieve very similar average score on the same IQ test, but assuming that the test is ‘culture fair’ the average person from Hong Kong would be able to score more highly than his or her North American counterparts on that same test. So if you have a Hong Kong national taking a US test, her IQ score and percentile (i.e. performance against the average) is likely to be over inflated compared to what it would have been if that same person had taken a ‘Hong Kong national IQ test’. This is so because the mean scores in Hong Kong would be higher than the mean score on Canadian or American tests.

This is why the concept of a national IQ test can be relevant. But in the internet age and in terms of online IQ tests, it is important to recognize that many markets are now global and boundaries meaningless. You are no longer competing solely against your country men and women. So the importance of a national IQ test is in fact falling. But I would argue that if you are serious about understanding your own intellectual abilities, you should be interested in knowing how you fare not only on a national IQ test relative to your own countrymen and women, but also on a global IQ test where people like you and me congregate online.

At we have established three scientific culture-fair IQ tests and we are building a database of national IQs by country as seen here. Because our site is relatively new, we do not yet have a sufficiently large number of observations for all countries to be able to derive accurate statistics for national IQs. We expect IQ ranges for the various countries to normalize over time as the number of observations increase. That said, the basic scoring scale on the individual IQ tests that we offer is not inconsistent with that which is used by Mensa in the USA and in several European countries. We are confident that our IQ tests will provide you with an accurate estimate of your fluid intelligence (Gf).

To try our culture-fair IQ test, click here.

Low IQ

Low IQ score are those below 90.
A score below 90 is usually considered a low IQ.

As discussed in previous posts, intellectual quotient (IQ) can be mapped out using standard scores. That is, IQ follows a normal distribution with a mean of 100 and a standard deviation which can be either 15,16 or 24 for the most popular tests. What we also know from the distribution of IQ scores is that 50% of people score above 100, while 50% of scores fall below 100. The beauty of the normal distribution is that the population of IQ scores can be described using only two variables: the mean (in this case 100) and the standard deviation (either 15,16 or 24). In other words, if we know the average score and the standard deviation of the test in question, we are able to calculate the percentile score (i.e. the rank) for any given IQ test result. For instance, assuming a standard deviation of 16, we know that an IQ score of say 97 places that person at the 42.56% percentile, which means that a score of 97 is higher than roughly 42.5% of the population.

Psychologists tend to agree that an IQ score falling between 90 and 109 is considered average. Scores between 80-89 are considered ‘low average’, while scores below this are considered ‘well below average’. People with IQs below 70 were historically considered to have an mental disability or to be cognitively deficient. Roughly 26% of the population has an IQ score below 90, and about 10% of the population have an IQ score below 80. About 3% of the population will have an IQ below 70.

An IQ score of 90 is not particularly high, but it is still withing the normal range. People with IQs in the low 90s have been known to be able to secure college degrees (albeit with a lot of work and determination) An IQ of below 90 can be considered a low IQ. So what is the relevance of IQ and in particular low IQ? Well, people will low IQ are statically much more likely to struggle in school and to drop out. This in turn could expose such low IQ persons to less favorable jobs and economics prospects. Low IQ persons, on average, tend to experience greater rates of unemployment, poverty and consequently tend to also have shorter lives. Low IQ  suggests that such persons will be less able to make intelligent choices when faced with tougher decisions and complex data.

Is low IQ a problem?

This depends. Many people with a low IQ in the 80s may end up living very honorable but tough lives in manual and unskilled labor. This in turn means that low IQ persons may not be able to afford the same level of education and healthcare to their children, but creates a self fulfilling prophecy of tougher environments which are likely to be less rich in opportunity for the offspring of the parents with low IQ.

This said, low IQ does not necessarily signify that individuals will be unable to live happy and fulfilling lives. Depending on how low the IQ level of course, moderately low IQ could simply be viewed as a headwind in life.

But very low IQ low 70s and below, could mean that individuals face a very serious intellectual disability which could lead to a greater requirement of intervention by caretakers. This can be a problem for the families of people with low IQs as low IQ individuals may never be capable of living fully independent lives.

Low IQ and the diagnosis of mental disability should not be made by looking at an IQ score only. People with lower levels of intellectual ability should seek a professional assessment of their condition rather than seeking out IQ testing online.

IQ standard deviation

IQ standard deviation
IQ standard deviation ranges from 15 to 24 on the most popular tests

Intellectual Quotient (IQ) is defined by the Oxford English Dictionary as: a number representing a person’s reasoning ability (measured using problem-solving tests) as compared to the statistical norm or average for their age, taken as 100.

This definition is simplistic in the sense that it ignores that origins of the IQ test. In the late 1890s, the Frenchman Alfred Binet devised a test based largely on verbal reasoning, that was requested to be developed by the Paris ministry of education in order to help schools ‘weed out’ children with a lower intellectual ability as the thinking at the time was that these children slowed down ‘normal’ or even ‘bright’ children during the academic year.

The goals of the ministry of education were not noble as there were no special plans for the children of lesser intellectual ability. These poor children were simply removed from the classroom.

In spite of the ugliness of the situation, the request by the Paris minister for a test of intellectual ability represented Binet’s window of opportunity to publish a test that he had developed several years earlier but which had never received any public recognition. Binet recognized that children of different ages would have different intellectual abilities. Binet’s thinking was that intellectual or mental ability (MA) for any given chronological age group (CA) could be ascertained by having the children of a particular age group perform a series of mental tasks and problems and determine an ‘average performance’ for that particular age group. His clever system led to an intellectual quotient which was calculated by taking the test taker’s MA and dividing into that person’s CA (and hence the intelligence quotient). At its beginning, the formula for calculating IQ was as follows: IQ = MA/CA. As can be seen from this equation, if the person’s MA was equal to that person’s CA, then the ratio would be equal to 1. Binet then multiplied the result by 100 to get an integer. This is how the average IQ score came to be 100. If a child’s MA age was in excess of his CA (i.e. the child was intelligent for his age group and was able to perform tasks at the same level as older children), then this particular child would have an IQ that was greater than 100 (the opposite also holding true). So if a 10 year old (CA of 10) was able to perform that same tasks as an average 12 year old (MA=12), then that child’s IQ score would be calculated as follows: IQ = MA/CA = 12/10 = 1.2 x 100 = 120. Although this calculation method was clever and simple to comprehend, it would actually break down under plenty of circumstances. In particular, what happens if a 75 year old (CA = 75) had the same MA as a 15 year old? Well according to this rudimentary IQ calculation, that person’s IQ would be 500! In fact, it was determined that adult IQs were reached in individuals of 16 years of age, although fluid intelligence is known to decline after our late 20s.

IQ standard scores and IQ standard deviation

In the 1930s, the calculation of IQ was revolutionized by American David Weschler, who along with a mathematician friend found that scores could be more robustly standardized by adjusting the raw scores achieved on a particular IQ test by the IQ standard deviation of the test. It would eventually be established that IQ scores were normally distributed and the properties of a standard normal distribution as such that the entire population distribution of IQ scores could be explained with two variables: the mean (or average) or the IQ standard deviation of the test.  The introduction of IQ standard deviation eliminated the problems highlighted above in the MA/CA example.

The purest way of determining what the standard deviation of the population of IQ scores would be to construct an IQ test and to administer it to an entire population and to mathematically calculate the standard deviation of the test results. This is in fact what test publishers look for when they publish a test (i.e. for the author of the test to have normed the test by attempting to administer it across a sample of test takers that are a truly random sample). There are plenty of different IQ tests and many have a different standard deviation. For instance, Cattell culture fair IIIa has a standard deviation of 16, while the Weschler Adult Intelligence Scale (WAIS) tests have a IQ standard deviation of 15 points. The Cattell verbal scale has a standard deviation of 24 points. fluid intelligence tests (click here) have an IQ standard deviation of 16 points.

IQ Genius

IQ genius: Einstein's IQ of 160 qualifies
Albert Einstein: IQ genius of 160 is matched by accomplishment.

You often hear the term ‘genius’ being bandied around. Even Apple use the term for their famous ‘Genius Bar’ at the apple store. But what does it really mean to be a genius? The Oxford English Dictionary defines genius  as noun meaning “exceptional intellectual or creative power or other natural ability”. So let’s take the different sections of the definition one at the time. First, exceptional intellectual ability can be measured by the Intelligence Quotient (IQ). Although imperfect, IQ tests attempt to standardize the measurement of human intelligence across a variety of facets of intelligence. That is, most modern-day IQ tests will test fluid intelligence (Gf), crystallized or verbal intelligence (Gc), visual intelligence (Gv), processing speed and short-term memory (Gsm). IQ tests may also attempt to measure mathematical ability. The global IQ score (G) can be understood as a global composite (ie. an average) of the scores achieved on the individual sections of the test. Most IQ tests are established to have an average score of 100, and may have a standard deviation (SD) of 15, 16 or 24 points (or anything in between), although 15 and 16 are the most commonly seen. The IQ distribution follows a normal distribution and we know that 50% of the population will have an IQ that is less than 100, whilst the other 50% of the population will have an IQ that is greater than 100.

Assuming that an IQ test has a standard deviation of 16 points, statistical properties tell us that roughly 68% of the population will have an IQ falling between the range of 84 and 116 (i.e. the average of 100 + or – the standard deviation of 16 points). Another way to look at the statistical properties of IQ is to say that anyone with an IQ falling between 90-109 is said to have an average or normal IQ. People with an IQ falling between 110 and 119 are said to have a ‘high average’ IQ, those with IQs between 120 and 129 are said to have ‘superior’ intelligence, while individuals with IQs above 130 are said to have very superior intelligence. IQs greater than 130 (16 SD) are found in roughly 3% of the population. Coming back to the definition of IQ genius, one could argue that people with an IQ greater than 130 would have ‘exceptional intellectual ability’ although this of course mean that a country like the United States, with a population in excess of 300 million, would have over nine million IQ geniuses. Clearly, this would not make any sense. Genius level IQ is typically associated with IQ genius scores in the 140+ range. Based on this cut off, IQ genius is found in one in every 161 individuals. On this basis, IQ genius can be found in just under 2 million individuals in the United States. An IQ of 140+ corresponds to a percentile in the 99.38% of the population.

IQ genius: is IQ alone enough to be a genius?

Technically, the Oxford English Dictionary’s definition of Genius has the word “or” between the three sections of the definition. On this basis, one could argue that an IQ of 140 is enough. But I would go on to argue that it takes more than a high IQ score to be worthy of the term genius. Achievement needs to match. There could well be roughly two million IQ genius in the United States, but I would argue that there are much fewer geniuses in the true sense of the word.

You can have a go at seeing how far off you IQ is from the genius level here.


Increase intelligence

Dual N-Back and IQ
Dual-N back may increase working memory and IQ

What distinguishes human beings from other animals? Although there are many traits that distinguish homo sapiens from other animal species such the ability to walk upright on two legs and our advanced communication skills, the principal distinguishing feature is our ability to think, learn and importantly to generate and pass on a growing body of knowledge to our successors. Knowledge is power and brain power – or intelligence – has been the pillar of success of our species. Intelligence has not only made human beings successful relative to other species of mammals, but intelligence and IQ are also important within the species. In other words, intelligent human beings tend to be more successful across a number of measures (e.g. wealth and health) than less intelligent human beings.

Finding a way to increase intelligence can therefore be seen as the holy grail of human success, at both micro and macro levels. So what is the evidence in terms of ways to increase intelligence? First off, let’s start with a refresher on intelligence, and its measurement. Intelligence and cognitive ability are captured by the measurement of the intelligence quotient (IQ).  Based on the Cattell-Horn theory of intelligence, general intelligence  can be broken down into crystallized (Gc) and fluid (Gf) intelligence. Gc can be likened to an accumulated body of knowledge and is improved through formal education and self-learning. You could argue that Jeopardy champions will have a very high level of crystallized intelligence. On this basis, one of the easiest way to increase intelligence is to stay in school longer and to pursue higher education and to remain intellectually inclined over one’s lifetime.  So improving Gc is actualy fairly straightforward.

Increase intelligence – the fluid kind

Based on Cattel-Horn theory, fluid intelligence (Gf) relates to our ability to solve novel problems – as in, problems that you will never have encountered before. You could argue that Gf is the ‘purest’ form of intelligence and can be liked to the raw processing power of the brain.  Individuals with high Gf have the raw brain power to be able to invest in their Gc. So Gf is really the pillar behind individual intelligence.

Gf is believed to be innate and cannot be improved through formal education. In 1990, Kyllonen argued that working memory capacity was highly correlated to fluid intelligence. Working memory, which is often used interchangeably with short term memory, can be likened to a mental scratch pad / or mental blackboard, where one can process mental calculations which are necessary for the effective solving of fluid intelligence problems. Because working memory and fluid intelligence are highly correlated, the theory goes that any exercises that would improve working memory would in turn boost fluid intelligence.

Dual N-Back to increase intelligence

The n-back task is a continuous performance task that is commonly used in neuroscience as an assessment in for working memory. The subject is presented with a sequence of audio and visual stimuli (i.e. a physical visual position of an object on a grid as well as a spoken / audio letter or number). The stimuli come sequentially and the test taker must remember the position of the visual stimuli or audio stimuli n-steps previously. The load factor n can be adjusted to make the task more or less difficult. In other words, you may be shown boxes appearing on a grid in North, East, South or West positions (including intermediary positions), whilst simultaneously hearing numbers being called out. The name of the game is to remember what the visual position and corresponding sound being called out were steps back. So if n=2, you would need to remember the position of the box and the sound two tries back.

A 2008 paper by Jaeggi et al. argued that practicing dual n-back improved working memory and that practicing dual n-back led to improvements in fluid intelligence (Gf) across a number of IQ tests. Although the results of this study are subject to controversy, this is the closest evidence that it is possible to increase intelligence – and fluid intelligence.

I have practiced dual n-back and have noted a definite improvement in my working memory and short term memory. There are plenty of resources on the web providing users access to dual n back training. Although free n-back resources are available, IQ Mindware ( offer a variety of paid-for apps which are specifically designed to help improve working memory and fluid IQ test results. Regular training will help increase intelligence by boosting  your working memory capacity. The latest version of the program includes ‘interference control’ which the developers argue enhances IQ transfer. The relevance of this feature is explained here.

Train regularly to increase your intelligence and assess your IQ gains by taking our web-leading fluid intelligence tests here.

New IQ test questions

New IQ test questions
New IQ test questions

Frenchman Alfred Binet developed the first of the modern day IQ tests. In addition to developing a framework for measuring intelligence, Binet taught the world that unlike the measurement of other human characteristics such as weight and height, IQ scores would necessarily be accompanied with a degree of error. The academic literature has gone one to validate Binet’s theory: the coefficient of correlation of one person’s IQ score with him/herself is 0.95. In other words, the same individual may experience some degree of IQ score variance depending on the test taken, the state of the test taker on the day of the test, and the same person’s score may even vary on the same test! On this latter point, practice effects are well known: test takers tend to boost their scores by an average of 8 points when taking the same IQ test twice. For this very reason, some high IQ societies such as Mensa will have you wait a full year before you are able to test again assuming that you failed to qualify the first time around. But increasing your score does not mean that you are increasing your general intelligence. So if you are serious about getting a true approximation of your global general intelligence score (G) it is useful to seek out new IQ tests with new IQ test questions to help zone in on your true IQ score.

Fluid intelligence and new IQ test questions

As discussed at length on previous postings, general intelligence can be broken down into crystallized vs fluid intelligence. Crystallized intelligence is more akin to academic smarts while fluid intelligence relates to one’s ability to solve novel problems. This is a critically important point: if you learn how to take fluid intelligence tests, you are no longer solving problems that are novel. For this reason, if you wish to zone in on your true level of fluid intelligence, you will need to seek out new IQ test questions which are novel. At, we have just published two new fluid intelligence tests with 100 new IQ test questions.

Test your IQ here today.

High IQ Society

High IQ society
Sununu is a member of the most exclusive high IQ society

What is a high IQ society? They come in many shapes and sizes. The most famous of the IQ societies is Mensa. This not-for-profit organization was founded in 1946 in England. The society is non-political and free of all social distinctions. The single criteria for admission is an IQ score in the 98th percentile (i.e. the top 2%). Mensa will accept a number of tests for admission and will also coordinate and administer group IQ tests.  Assuming a standard deviation of 16, this implies an IQ of at least 132.

High IQ Society: more exclusive than Mensa?

Intertel is a high IQ society formed in 1966. The society accepts members with an IQ score in the 99th percentile or top 1% of the population. The society also publishes a monthly journal called Integra, the Journal of Intertel. The minimum IQ score is about 135.

The Triple Nine Society is a high IQ society founded in 1978 for individuals with an IQ in the 99.9th percentile (IQ of about 149 or greater, which represents a rarity of 1 in about 1000 people). The International Society for Philosophical Enquiry, founded in 1974 also has the same admission criteria at the 99.9th percentile.

The Prometheus Society accepts members with an IQ of c.160 which corresponds to 1 in 30,000 people (99.7th percentile). It’s official publication is The Gift of Fire.

The most exclusive society is the Mega Society which accepts members in the 99.99th percentile, which corresponds roughly to 1 in a million people.  The corresponding level of IQ is not accurately measurable but most likely corresponds to an IQ of c.170. The Mega Society currently has 26 members.

There are of course plenty of high IQ societies which accept test scores in that are lower than the 98th percentile.

To see whether you might qualify for one of these societies, give our IQ online IQ test a try here.