IQ-Brain Blog

Test the Nation

Test the Nation final episode
Test the Nation has been discontinued in the UK since 2007

Test the Nation is a concept and television show that first appeared in the Netherlands in 2001. The purpose of the show is to test the nation’s IQ in a form of National IQ test.

Test the Nation would eventually find its way to the UK , Ireland and Canada although the UK BBC version of the show, hosted by Anne Robinson would quickly become the most famous of these national IQ tests.

The format of the show would take the turn of a studio audience taking a live IQ test in order to ascertain the nation’s IQ. It eventually became possible for television viewers to interactively participate in the show by answering questions online.

Test the Nation was a timed IQ test which included questions included involving among others, memorization exercises , analogies and word unscrambling.

From the perspective of an online IQ test developer, the BBC’s test the nation was very poorly designed. It contained a mixture of questions that measure both fluid and crystallized intelligence, in addition to general knowledge which is of little relevance when it comes to the measurement of intelligence. On this basis, the test was really a confused crystallized IQ test that was totally geared to a UK audience and I question whether the score would have correlated highly with a professionally administered IQ test.

Test the Nation: a confused IQ test

Administering a verbal or crystallized IQ test has its merits although the test questions then end up favoring individuals with higher education. Further, Test the Nation’s questions were not at all applicable or fair to the UK’s immigrant population (c.12% of the UK population was foreign-born in 2010). As an example in the scrambled word section of the 2003 test, the following anagram: nraelpeoa had to be solved.

The the Nation was making the assumption that the above anagram would result in an unbiased question but the developers were clearly misguided. Many parts of the world would never even have thought that the word aeroplane could be formed from the above, particularly as the “airplane” is the more popular spelling globally.

Further, knowledge based questions based on facts of the United Kingdom have no place in IQ testing. For instance, another section of the test was called “Everyday Symbols”. In this section, pictures of items like road signs were distorted or modified and the test taker’s’ task was to identify the correct version of the symbol. As an example, the test taker would have needed to identify whether the cover of the British Passport was correctly drawn, or whether the font for the symbol of the BBC was correctly depicted. These types of questions are more suitable for a pub quiz than for an IQ test and have little to do with general intelligence. BBC’s Test the Nation was discontinued in 2007, and I see no reason to revive it in the format that it had.

I am a believer that a National IQ test that is the most interesting would have been a fluid IQ test with heavy emphasis on Gloaded novel IQ questions.

Similarly, culture-fair fluid IQ tests are much more applicable to online IQ testing, with a global audience.

To test your fluid IQ effectively, click here, provided by

Child Genius

Child Genius: math
Child Geniuses who recorded perfect scores at the mathematics Olympiad (2011)

A child prodigy or Wunderkind is a person who at an early age, develops one or more skills that are far beyond the norm for their age. A child prodigy needs to be a minor (i.e. less than 18 years of age) who is able to perform at the level of a highly trained adult in a very demanding field of endeavour.

The above definition, taken from Wikipedia, is interesting as it brings us back to the concept of intelligence and to the calculation of the Intellectual Quotient (IQ) in particular. As seen in previous posts, Frenchman Alfred Binet first coined IQ as representing the ratio of that person’s Mental Age (MA) to their Calendar Age (CA). Binet’s formula for IQ was simple and elegant:

IQ = (MA/CA) x100

Which means that a person will Mental Age which exceeded their Calendar Age would have an IQ greater than 100, while someone who performed at a level lower than their age would have an IQ lower than 100.

So if a 10 year old (CA = 10), was found to have a Mental Age of 20, then that child’s IQ would be:

(20 / 10) x 100 = 200

Clearly, an IQ of 200 would be exceptional most likely correspond to a child genius (assuming the other real accomplishments were to match). Although Binet’s quotient method would eventually be replaced by standard scores, the old equation is helpful in considering what IQ is really all about, and where one might want to start looking for potential child prodigies and child geniuses.

Coming back to the definition of child prodigy, it is clear that IQ alone is not enough to warrant calling a child a genius. One must look for accompanying accomplishments which would justify the Child Genius label being employed.

Mozart (IQ estimate of 160), was a child prodigy and child genius, having written concertos by the tender age of eight. James Sidis, on the other hand, set a record as the youngest person to ever enroll at Harvard College by the age of 11. So real life accomplishments, not just being good at taking IQ tests, remain critical to the designation of a child genius.

Child Genius: the search for Britain’s biggest brainbox

In the UK, television station Channel 4 has recently launched its fifth series of “Child Genius”, which is the hunt for Britain’s brightest child – in collaboration with Mensa. Many of the children who appear on the show as clearly bright, but few are exceptional talents that would warrant inclusion into a list of child prodigies.

This program is highly entertaining, although the entertainment does not just emanate from the impressive intellectual ability of some of the children, but also due to the total unreasonable parents that appear on the show.

A child genius needs to be encouraged and be given the opportunity maximize their talents, but many parents on the show push their children so hard that some look pale and awkward, and are only likely to struggle to fit in socially in their teens.

Parents should focus on raising well rounded children instead of book worm nerds, that end up becoming dorks. Other parents let some of these children walk all over them, creating a perfect breeding ground for some of them to become arrogant teenagers.

The Child Genius is a good program, but the show should accord points to children who have real talents (e.g. music, or otherwise) as opposed to being book worms. Parents of child geniuses need to remember that “All work and no play makes Jack (and Jill) a dull boy (girl”)

Do you think you might be a genius? If so, you can test your hand at our fluid intelligence IQ test here.

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IQ and EQ

IQ and EQ: who can spot shades of emotion?
IQ and EQ: can’t higher IQ people better discern between shades of emotion?

IQ and EQ are two different concepts, but are related. But let me provide you with some background on the two concepts first.

IQ stands for “Intellectual Quotient”, which is also a term used in every day life to mean general intelligence. The term was coined by Frenchman Alfred Binet in the late 1800s. Binet was asked by the Paris ministry of education to devise a test which could help weed out intellectually slower children from the classroom in an attempt to ensure that normal or bright children would not be held back unnecessarily.  So Binet came up with the concept of “Mental Age” or MA which would be compared to the child’s “Calendar Age”. The ratio of the two – i.e. (MA/CA) x 100 – would become known as the Intellectual Quotient. In the 1930s, this old quotient method would be replaced by standard scores, which eliminated several problems with Binet’s original equation. But the term IQ would remain nonetheless and is still widely used today when referring to someone’s intellectual ability or intelligence. General Intelligence, can be thought of as the raw processing power of the brain. IQ is simply a score which attempts to describe one’s mental capability based on a series of tests and examinations which are believe to represent the core components of intellectual ability. Although there are many types of intelligence, the key components are: (1) crystallized intelligence (Gc); and (2) fluid intelligence (Gf). Fluid intelligence can be further broken down into sub components including: (i) Processing Speed (Gs); (ii) Visualization (Gv) and (iii) short term and working memory (Gsm). As we will see, IQ and EQ are very different. IQ measures pure brain processing power, and does not tell us whether someone is kind, nasty, fearful, deviant or forgiving. IQ tells us whether someone has high brain capacity – not whether someone is likable or uses their brain power for good.

Many people are quite uncomfortable talking about IQ because of the fact that all are not created equal when it comes to brain power. Although the average level of general intelligence in most advanced countries is usually set at 100, is it known that IQ follows a near normal distribution which means that 50% of the population have an IQ greater than 100, while the other half have an IQ lower than 100. But this fact in itself, is not distressing. What makes some people uncomfortable about IQ is the fact that there is a positive correlation between IQ level and outcomes in life, but specifically successful life outcomes. For instance, people with high IQ, on average, will tend to make more money, live longer, have smarter offspring and in better health and are less likely to become incarcerated or even get divorced. The simple fact is that higher intelligence allows people to make better choices, which can positively impact life outcomes.

The term Emotional Intelligence (EI) or Emotional Quotient (EQ) is much newer than its IQ counterpart.  Emotional Intelligence can be defined as the ability to monitor one’s own and other people’s emotions, to discriminate between different emotions and to label them appropriately, and to use this information behavior to guide thinking and behavior. Although EI was written about in the 1960s, the concept was popularized after Gardner’s publication Frames of Mind: the Theory of Multiple Intelligences. In short, the theory on EQ was propagated by academics who were discontent with the literature on IQ. IQ and EQ are not only different concepts, but the concept of EQ was created in response to grievances with the concept of IQ. That is, several academics including Gardner have always struggled to accept that IQ or General Intelligence would be the over arching guiding variable of success for humans.

IQ and EQ: the truth is that higher IQ people will be able to see the shades of grey

The reality, is that EQ boils down to emotional awareness, judgment and general sensitivity. Studies have shown that people with higher IQs, on average, tend to be more socially intelligent. If people with higher IQs (on average) were socially awkward, then how does one explain the fact that higher IQ people are more successful in not only work, but relationships also? This is not to say that people with extremely high IQs may not find it hard to fit in socially. Indeed, any extreme deviation from the average my make ‘fitting in’ a tad more difficult. What I am saying however is that the law of averages predicts a positive correlation between above average intelligence and social ability and therefore EQ.

IQ and EQ: it sounds like they might be related? But people with high IQ may be able to detach themselves more effectively from the emotional side of a debate to make decisions based on objective criteria. This approach may of course be difficult to take for people who tend to be guided by emotions. In other words, higher IQ people may, on average, be as emotionally aware as anyone else, but may be better able to resist making decisions based on emotional or subjective criteria.

It occurs to me that debate should not be about IQ vs EQ. But rather IQ and EQ.

To test your IQ, click here.

Cognitive ability

What is cognitive ability? The free dictionary defines cognitive ability as: The mental process of knowing, including aspects such as awareness, perception, reasoning and judgment.

Cognitive ability is nothing more than a set of mental abilities which help guide our decision making and success rate in every day life across different social settings and situations Cognitive ability is perhaps slightly wider than pure intellectual ability or IQ because of the inclusion of awareness, and judgment. The latter two components are closely associated with the concept of emotional intelligence (EQ).

Cognitive ability is more than just IQ. For instance, someone can have the absolute highest mathematical ability (typically associated with a high IQ) but could often end up saying the wrong thing at the wrong time. This is both a problem with perception, awareness and judgment (often referred to as sensitivity) but can also be linked to conditions of the brain (e.g. autism). Conversely, someone may be both well rounded, intelligent and successful socially in intellectual circles, but may come off as being insensitive and arrogant in environments where people are less high achieving. Again, this reflects a lack of social awareness and emotional control.

Cognitive ability
Cognitive ability encompasses a complex set of mental processes. IQ is key.

So how does one measure cognitive ability? Is there such a thing as a cognitive ability test? Well, there is a test named “the Cognitive Ability Test ” (CogAT, or CAT) which is a standardized K-12 test in the United States which seeks to test (1) verbal, (2) quantitative and (3) non-verbal skills and is often administered in conjunction with the Iowa test, to predict school achievement. The cynic in me says that this is little more than a performance and verbal IQ test, and it has been established that there is a correlation between this test and IQ tests.

Measuring Cognitive ability

So how does one go about establishing cognitive ability? I believe that there is no one test that will provide an accurate measurement. Measuring cognitive ability objectively starts with the measurement of general intelligence, which is a key component to all the rest. It has in fact been shown that IQ and EQ are often related, and a 2012 study using brain scans of Vietnam veterans showed that brain lesions in areas affecting reasoning, not only diminished intellectual capacity as measured by IQ, but also decreased performance on EQ related tasks. Hence, although IQ and EQ are distinct concepts, the two are in fact correlated.

Measuring cognitive ability therefore starts through the (reasonably) objective measurement of IQ, and followed by observational evidence around someone’s success in various social settings: from the family, to relationships, friendships and the workplace.

You can test your IQ here at

Is IQ hereditary?

Is IQ hereditary?
Is IQ hereditary? Chimp studies add support to the 50% heritability conclusion in humans

Is IQ hereditary? Although many people have asked the question, few people have wanted to hear the real answer to this question.

In 1987, Shockley, a Nobel Prize winner in Physics repeated the claim from the controversial book “The Bell Curve” that IQ was in fact genetic. So is IQ hereditary really? Let’s turn to the academic literature to find out.

One interesting place to start is studies of identical vs fraternal twins. Identical twins have almost identical DNA and cannot be told apart in this way. Fraternal twins, on the other hand, although born at the same time, are just like any other pair of siblings in that they share 50% of genes.

Is IQ hereditary then? In a study as early as the 1970s, Plonmin and Petrill found that 50% of IQ is likely to be heritable. This is so because the IQ score for identical twins was very highly correlated compared to that of fraternal twins, despite either type of twin (across populations) being born at the same type and the assumption that both types of twins would like be reared by the same care-taker and benefit from equal environmental settings.

Adoption studies are also interesting in this regard. Adoption studies have shown that the correlation of coefficient between the IQ of identical twins was 0.86 (which is very high), which drops to 0.76 (still very high correlation) if the siblings are reared apart.

This compares to an IQ score correlation of 0.47 for siblings reared together (medium strength correlation), dropping to 0.22 for siblings reared apart (weak correlation). The correlation between the IQ of adoptive parents and their children is 0.19, which is even lower than siblings reared in different households.

Is IQ hereditary? It would appear so. In a 1997 study, Petrill revisited the earlier studies with refined statistical procedures. This study found that the heritability of IQ was 50%.

In a 1998 study, Bouchard found that the correlation of IQs of unrelated children reared together was 0.28, which dropped to a near nil value in adulthood.

Is IQ hereditary in animals?

A new study by William Hopkins of Georgia State University has looked at whether IQ is genetic through chimp studies. The results closely match those found is humans. That is, more intelligent chimps are found to have more intelligent offspring, and a statistical analysis of the results suggests that the estimate for heritability is 50%.

Coming back to the original question: Is IQ hereditary? I would appear so, for at least 50%. And importantly, the heritability component prevails  in adulthood.

At, we provide three advanced fluid IQ tests which mirror the level of difficulty and time pressure that can be expected from tests from high IQ societies such as Mensa. You can test your IQ here.

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IQ and religion

IQ and religion are negatively correlated
IQ and religion are negatively correlated

What is the relationship between IQ and religion?

We have all heard from staunch atheists Christopher Hitchens and Richard Dawkins who go out of their way to combat religiosity and to preach the virtues of atheism. Are these atheists right about their views? Are the atheists smarter than others?

These ‘preacher’ atheists attempt to use rational arguments and intellectual arguments to prove their points. Although one’s level of religiosity boils down in part to personal belief systems and up-bringing, the question of whether IQ and religion are related is an interesting one and could help explain why certain groups (e.g. academics) are often at the centre of atheist debate.

A recent meta-study by the University of Rochester looked at 63 scientific studies on IQ dating back to 1928 in an attempt to ascertain the link between IQ and religiosity, Of the 63 studies, 53 (83%) found a definite strong negative correlation between IQ and religiosity, while only 10 showed  a positive one. The relationship between IQ and religion is therefore clear: the higher people’s IQ, the lower the likelihood of being religious.

The study also suggested that intelligence by the age of eight years of age was also a good predictor of whether the child would grow up and turn away from religion.

IQ and religion: what does this mean for IQ scores?

This is not the first study to establish a negative correlation between IQ and religion. A number of studies have shown that atheist groups tend to outscore dogmatic religious groups by 6 IQ points, with atheists having a mean IQ score of 103 versus 97 for religious groups.

These results should come as no surprise: people who are religious are less likely to be guided by deductive, scientific and logical reasoning which are all characteristics associated with greater intelligence. Higher IQ is also associated with a propensity to question and challenge assumptions, which is inconsistent with the concept of ‘faith’ and religious belief generally.

To find out about your IQ, click here.

Average Harvard IQ

Average Harvard IQ
Average Harvard IQ is difficult to precisely estimate

Harvard is one of the World’s premier higher education establishments. Harvard University was established in 1636 and today admits has 7,000 undergraduates and 14,000 graduate students.

As most US undergraduate degrees last four years, it is easy to work out that Harvard should therefore be admitting 1750 students per year to keep the undergraduate student population stable at 7,000 (assuming no attrition). However, 2,175 were admitted in 2013 which suggests that either the drop / non completion rate is high, or that Harvard is trying to grow the size of its undergraduate student body.

But Harvard is an intellectual elite school. 27,500 people applied for entry but only 8% were admitted in 2013.  On this basis, it comes as no surprise that many people are intrigued as to what the average Harvard IQ might be?

One way to estimate what the average Harvard IQ might be through SAT scores. SATs have been described by Harvard educator Howard Gardner as thinly disguised IQ tests.

It has been reported that most Ivy league admissions officers focus on the Math and Critical Reading sections of the SAT test. To estimate the average Harvard IQ, one should therefore start with understanding the average admission criteria.

The bottom 25% of the class of 2013 had the following scores on the different sections of the SAT 1.

  • Math: 710
  • Critical reading: 700
  • Writing: 710

The above scores sum up to a total composite score of 2120. Although this score represents the bottom 25% of newly admitted Harvard students, such a score in fact corresponds to the 97th percentile of scores for the population of SAT test takers as a whole. In other words, the top 3%.

If SAT scores were exactly analogous to fluid IQ scores, the top 3% would correspond to an IQ score of 129 (assuming a standard deviation of 15) or an IQ score of 131 (assuming a standard deviation of 16).

Coming back to the class of 2013 admissions data, students at the 75% percentile (i.e. the top 25% of new Harvard students) had the following SAT scores

  • Math: 790
  • Critical reading: 800
  • Writing: 800

For a total composite score of 2390. This translates into a  combined score that is well inside of the top 1% of the population. In IQ terms, the top 1% of the population would translate into a score of 134 (15 Standard deviation) and 137 (16 SD).

On the basis of the SAT figures above, and knowing the admissions values for the 25th and 75th percentiles, we can guess roughly that the average SAT score at the 50th percentile (i.e. the average) may be somewhere around the 2200 mark, which translates roughly into the 98% percentile of the top 2% of  SAT test takers.

The corresponding IQ in the top 2% would be 130 (15 SD) or 132 (16 SD), which happens to be the threshold for admission into Mensa.

Estimating average Harvard IQ – are SATs scores the answer?

Prior to 1994, Mensa used to accept SAT scores as prior evidence for qualification to the society. SAT scores are no longer accepted by American Mensa as it is no longer believed that modern-day scores correlate with IQ.

I have seen estimates online of average Harvard IQs being as high as 140 and as low as 127. So what is the answer for the true average Harvard IQ? No one knows for sure.

One valid argument is that is it not entirely correct to equate the distribution of SAT scores with that of a fluid intelligence test. This is so because IQ distributions should be based on the general / overall population, whereas SAT scores distributions leave out the lower left hand tail of the general population. That is, people who struggle academically and with low IQs are less likely to sit an SAT test. So based on this argument, one would conclude that achieving a high percentile on an SAT distribution (relatively to filtered distribution which excludes the lowest IQ scores) corresponds to an increased percentile relative to the general population. In plain English, a SAT score around the 2,200 (98th percentile relative to other SAT test takers) for instance, might equate to a significantly higher IQ score relative to the general population.

However, this distribution bias effect might well be negated by the fact that you can prepare for the SAT test, whereas you should not have any indication of the contents of a properly administered fluid IQ test. In other words, the test prep element could well negate any distribution-related biases resulting from the comparison of fluid IQ and SAT score distributions.

On the basis that you can prepare and study for an SAT test, but that you cannot effectively do the same for a fluid IQ test, I would contend that the average SAT percentiles are likely to be over-inflated relative to fluid IQ scores. The only real challenge to this hypothesis is that there is little supporting evidence that SAT test prep reliably produces tangible results. Nevertheless, it is irrefutable that you can study for the SAT, which this is likely to lead to score gains relative to a fluid IQ test.

Coming back to SAT scores, for which the average eventual Harvard class of 2017 has a score in the top 2% of the population, of test takers this is probably an upper bound for the corresponding average level of fluid intelligence. I propose that an IQ score of 127  (95.4% percentile with 16 SD) as the average Harvard IQ sounds plausible. So the average Harvard university student would fall short of the IQ level required for Mensa (132 assuming 16 SD).

This is not to say that Harvard would not have plenty of students with Mensa (132+) and genius-level IQs (>140), but rather that the percentile achieved on the SAT is likely to be high compared to that cohort’s corresponding average level of IQ.

Click here to test your true fluid IQ.

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Average IQ of university students

Average IQ of university students is 113
Average IQ of university students in 113

How much brain power does it take to get through College in a Western system of education? Before turning to this question, let’s brush up on general intelligence or IQ and its properties. Within a country, the average IQ is set to 100 points, and roughly half of the population will have an IQ greater than the average of 100, while the other half will have an IQ score which is lower than 100.

The distribution of IQ takes the shape of a ‘Bell Curve’ which is the layman’s way of saying that IQ scores are normally distributed. Based on millions of results for the most popular IQ tests in the United States, it is thought that the standard deviation of the test scores for the population as a whole is likely to be 16 points, although the standard deviation of IQ scores can vary from test to test.

Based on the statistical properties of the normal distribution, assuming a 16 point standard deviation, we know the following:

  • 68% of the population will have an IQ score which is one standard deviation away from the mean score of 100 (i.e. IQ scores ranging from 84 to 116 points)
  • 95.4% of the population will have an IQ score which is two standard deviations away from the mean (i.e. IQ of 68 to 132)
  • 99.7% of the population will have an IQ score which is three standard deviations away from the mean (i.e. IQ of 52 to 148)

So what this tells us is that the farther away we get from the mean score of 100, the more rare the observation of an IQ score.

The average IQ of university students – the data

So let’s come back to the question of college and what the average IQ of university students is.

In the famous but controversial book “The Bell Curve”, Murray and Hernstein observed that the average IQ of university students had  increased from 111 IQ points in the 1930s, to 113 IQ points by the time their published their book in the 1990s. In other words, the average IQ of university students is less than one standard deviation away from the mean (assuming a 16 points SD).

An IQ score of 113 points is at the 79% percentile, meaning that in the United States, this translates into the top 21% of the population. In other words, one in five people have the average IQ of a university student.

But this is not to say that you need an IQ of 113 points to get into a university and stay there. In fact, OECD research from 2010 suggests that in OECD countries,  nearly 40% of young people between the ages of 25-34 have been through tertiary education (university equivalent education). The proportion of Americans in this age bracket with college degrees was over 40%, increasing to 55% of the population in Canada and nearly 65% of the population in Korea! In the United Kingdom, 49% of young people enrolled University a few years ago to beat the proposed tuition fee hike to £9,000 per annum.

The point is simple, you will probably struggle to get into a university which is moderately competitive if your IQ is 100. In fact, this is corroborates by a study which has found that IQs of 90 are rarely observed in either college graduates or professional jobs. A further study had shown that the average IQ of people who had completed 2/3 of their college education was 104.

On this basis, you will probably get into a not-so-competitive university with an IQ of 100, but that you may struggle to complete a reasonably academic degree if your IQ is less than 110 points.

The average IQ of university students will further depend on the university and the course that is taken.

To find out what your true IQ score is, click here to take our test.

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Mensa and

Mensa and
Mensa and – an unsustainable pair

Mensa and have partnered up to create a dating site for the cognitive elite. The idea came about as a survey of singletons revealed that ‘brain power’ and partnering up with someone with similar intellectual ability ranked very high, or even as a ‘must have’ when selecting a partner. Here is why I believe that this is a poor idea.

First of all, Mensa level IQ is 132 (assuming a standard deviation of 16 points) which corresponds to an IQ in the top 2% of the population. However, at the ‘very superior’ level of IQ, men outnumber women by a factor of 2:1. So although men and women have similar average IQs generally, the picture changes dramatically beyond the 130 range.

In isolation, a partnership between Mensa and sounds like a clever idea, in practice, this will result in a dating pool in which men significantly outnumber women. So this might in fact be a great tool for highly intelligent women who prefer brains over brawn, although sustainability of such a site is questionable due to the natural gender imbalance at the ‘gifted’ level of IQ.

Further, it is difficult enough to find someone that you connect with that fishing in such a small pool is likely to make it even more difficult to find a partner.

Mensa and – it just doesn’t add up

Mensa and is an interesting, but pointless joint venture.

Think about the consequences of this dating disaster: what if a man with an IQ of 133, ends up dating a woman with an IQ of 138. What will arguments look like? Will the woman ignore the man because his IQ is less than her own?

One is much better off looking for a partner with a similar education background to ascertain brain power than knowing your partner’s exact IQ. If a woman is looking for a clever man, or vice versa, that person is much better off looking for ‘graduate education’ or Ivy League education as a proxy for the intellectual of a potential mate.

At, we provide IQ testing which mirrors the level of difficulty of Mensa-administered IQ tests. If after having identified your mate, and guesstimated their IQ, you still have doubts, you can take our IQ test here.

IQ and age (part III)

IQ and age - declines are inevitable
IQ and age – Fluid IQ diminishes as we enter into middle age

This is my third posting on the interesting topic of the interplay between IQ and age. As discussed in my last posting, our fluid intelligence (that is, our ability to solve novel problems) will expand during childhood, slow down after the age of 16 and peak at 25, before beginning a gradual decline thereafter. That’s right, our fluid IQ and fluid intelligence will decline into adulthood.

So what does this mean? Fluid IQ and age are positively correlated between the ages of 0-25, and negatively correlated from the age of 25 until we die. In absolute terms, our raw intelligence (as measured by fluid IQ) will increase from birth until our mid 20s, before declining thereafter.

But when one thinks about IQ measurement, is it important to consider both absolute and relative elements of the IQ score. This is so because in absolute terms, most 25 year olds will be more intelligence than children under the age of 10, although in relative terms the comparison of intellectual abilities between the two groups requires a relative dimension.

That is, a 10-year old who is able to think and process information like a 16 year old would be exceptional for her age – and this would be reflected in an exceptional IQ score. In absolute terms, this child would perhaps not be as clever as a bright 25 year old college graduate, but in relative terms, would be leaps and bounds more advanced than her age-related peers and probably a significant proportion of 25 year olds.

Conversely, a 25 year old who failed to complete high school because he struggled with the difficulty of the material would most likely be found to have a low IQ score, both in absolute and relative terms.

High IQ societies such as Mensa will typically make adjustments for the age of the test taker, but in childhood through to early adolescence only.  That is, the bar for achieving a score in the top 2% of IQ will be lower for the 12 year old taking the test, relative to the 25 year old. In fact, after the age of 16, test takers are measured on the ‘adult’ IQ scale.

IQ and age – relative and absolute scores needed

The problem is that this age-correction does not take place past the age of 25, which means that new joiners to Mensa who are not supplying ‘prior evidence’, which means proof of a score in the top 2% at some point in that individual’s lifetime, are much less likely to be in their late or early 40s than say, early 20s.

So in fact, middle aged people taking a fluid IQ test will be measured against the population in absolute terms (and thus against peak adults) and will get no insight as to how well they have maintained their fluid IQ relative to their age-related peers.

At, we are working on establishing a scale which would provide this level of color. We expect to be able to publish the results of this study by early 2015. That is, we hope to be able to give middle aged and golden aged individuals both a relative picture as well as the absolute picture of how well they are fairing when it comes to IQ and age.

In the meantime, you can test your absolute IQ score HERE,