IQ-Brain Blog

IQ test Mensa

IQ test Mensa fluid intelligence tests
IQ test Mensa-style

Mensa is one of many high IQ societies. Membership is open to individuals who manage to score in the top 2% of all test takers on a long list of approved IQ tests. You can either send in a past IQ test score for admission or you can book a Mensa-administered IQ test.

So what do the Mensa IQ tests look like? Well, you will need to allow up to three hours for the entire testing process. You will receive an invitation with a time and date for the assessment. You will enter a room and take a seat. A Mensa volunteer will then proceed to explain the process and to reiterate the necessary scores to gain admission to the society. IQ test Mensa-style involves two tests: (1) a culture-fair IQ test and (2) a verbal intelligence test. The Culture-fair IQ test measures your fluid intelligence and is usually based on Cattell Culture-fair IIIa but can also resemble Raven’s Progressive Matrices (RPM). The Cattell test has a standard deviation of 16, which means that a score of 132 is necessary to qualify for membership. IQ test Mensa-style also comprises a verbal IQ test which may have a standard deviation of 24, which means that an IQ of 148 is necessary to qualify for membership.

IQ test Mensa-style – what is different?

IQ test Mensa-style differs from other types of tests in that the society places significant emphasis on speed of responses. One the culture-fair IQ test, you end up with less than 16-20 seconds per question. The time pressure is perhaps the most shocking surprise for test takers.

At, we aim to provide the most accurate culture-fair testing on the web in the style of IQ test Mensa. We have created three different tests (each comprising 50 questions) with a similar level of difficulty and time pressure as a Mensa-administered group IQ test.

You can try all of our test HERE.

Test my IQ

Test my IQ – I am too broke!

Test my IQ - no need to pay loads
Test my IQ

IQ testing is a business. Psychologists charge up to $1000 for these tests. Although we concur that in theory, the best of the clinical psychologists will probably be able to test IQ with a higher degree of accuracy than group-administered tests (e.g. Mensa offers such tests) or what is available online, the purity of the IQ measurement is easily compromised by the level of subjectivity applied by the assessor. In fact, research has shown that IQ scoring for the same individual on the same test can fluctuate by 8 points depending on the assessor. So there reality is that there is a risk that you can dish out $1k to be told that you have an IQ of 120, which could really be as low as 112, but as high as 128 depending on the competency of the psychologist who is administering the test.

Test my IQ – group testing style

If you want to join a high IQ society like Mensa, you will need an IQ that is in the top 2% of the population for any of the recognized IQ tests that are out there. If you are lucky enough to have been administered such an accepted test in school, and scored in the top 2%, all you need to do is to show Mensa proof of this score and you will be invited for membership. If on the other hand, you have never taken an IQ test, than you will need to make an appointment and to go into a classroom on a date and time which may or may not be convenient to you in order to sit a group-administered IQ test. At least here the cost is modest, but many people find it very inconvenient to plan, book and to physically get up on a Saturday morning to go into a room with strangers and spend three hours of your life being subjected to IQ testing, not to mention that you must then wait up to 10 days for the result! I personally prefer these types of tests as there is less subjectivity involved in the scoring, but it takes a motivated individual to go out and seek such an assessment.

Test my IQ – cheaply and accurately

For the vast majority of us, we would like to be able to sit in the comfort of our own homes, spend a limited amount of money and time and to obtain what is likely to be a reasonably accurate result. “test my IQ” is all good and well, but I want a result that is at least plausible. But what is the point of taking an easy online IQ test and obtaining an inflated score only to find out that your ‘true’ IQ score in a proctor-administered test may be much lower?  Similarly, if you think that you may want to try your hand at gaining Mensa membership, or think that you may need to take an IQ test for work or even simply because you are a curious soul and want to find out what your ‘magic number’ may be, then it is not unreasonable for you to want to have a dry run at one of these tests from the comfort of your own home.

The list of IQ tests providers online is a long one and there are a few good ones, but you need to have taken a group-administered test to understand whether the site in question is any good. So by the time you have spent the money, only then will you discover how good the particular site is. At, we aim to provide the most accurate fluid intelligence IQ testing on the web. More specifically, we have based our methodology on Mensa-style level of difficulty, time pressures and more importantly, IQ-test scoring. I test my IQ, will you? To try our IQ test, click here.

Fluid vs crystallized intelligence

fluid vs crystallized intelligence
Learning about fluid vs. crystallized intelligence

Fluid vs crystallized intelligence. What’s the difference? General intelligence can be decomposed into (1) crystallized and (2) fluid intelligence. Fluid vs crystallized intelligence are simple concepts to grasp. Crystallized IQ relates to general knowledge and verbal ability, which is accumulated over time in formal education. Crystallized IQ test questions may include grouping synonyms, explaining the meaning of words, identifying antonyms, working with analogies or perhaps even filling in the blanks in a paragraph with missing words.

Fluid intelligence, on the other hand, relates to one’s ability to solve novel problems. The latter type of intelligence cannot emanate from materials taught in schools. Fluid IQ test questions may include identifying patterns, finding a missing sequence and spatially manipulating complex figures. So when I test my IQ, it is quite possible to expect different levels of performance on crystallized vs fluid intelligence components of the test.  That said, the two measures should be correlated, but more in one direction that the other.

Fluid vs crystallized intelligence: the correlation

Research on intelligence has shown that individuals with a strong fluid intelligence are more likely to also have strong crystallized intelligence rather than the other way around. The reason being that fluid intelligence is largely innate and peaks in our mid 20s, only to beging a gradual decline thereafter. Someone who has strong fluid intelligence and is able to make sense of the world they live in, and will possess an uncanny ability to solve novel problem around them.  On average, these individuals are more likely to be able to breeze through education with ease and therefore to accumulate a greater body of knowledge than someone who struggles to see the logic in academic materials. For this reason, high fluid intelligence is strongly positively associated with crystallized IQ.

But this is not to say that all individuals with a Masters degree or a PhD will have a high fluid IQ. Some Individuals with low to moderate fluid intelligence may well be extremely motivated and hard-working which means that they may be able to succeed at obtaining higher degrees, which may lead to a reasonably high crystallized IQ result, despite having an average level of fluid intelligence. There really is no substitute for hard work and motivation.

So in simplistic terms, this explains the interrelationship between fluid vs crystallized intelligence.  At, we believe that fluid intelligence is a better measure of the raw processing power of the human brain and is better suited to a global internet audience with differing levels of education. That is, our fluid IQ tests do not confer any form of advantage to people with higher levels of education.

Fluid vs crystallized intelligence are easy enough concepts to explain. But testing these components individually are clearly subject to measurement error.

At, we aim to provide the most accurate IQ fluid intelligence testing on the Web. More specifically, we have created a series of tests which aim to replicate the level of difficult and time pressures that would be associated with a proctor-administered tests or those administered by high IQ societies such as Mensa.

To take our IQ tests online, click here.




Highest IQ – the measurement challenges

Highest IQ - measurement is challenging
Highest IQ measurement challenges

This articles highlights some of the challenges associated with measuring human intelligence and in particular those associated with the measurement of the highest IQ. First, unlike measuring height, weight and even human speed on a 100 meter dash, measuring IQ (and particularly the highest IQ) is a difficult endeavor. Alfred Binet – one of the pioneering forefathers of modern IQ tests – pointed out that measuring human intelligence was not as clear cut as measuring other human traits and characteristics, and that it was therefore necessary to accept a degree of error in the measurement of IQ. This assertion was one of Binet’s finest.

Another important concept in this debate is the diversity of IQ tests and associated scales. There are several different and well-respected IQ tests. Examples of well-known tests include Cattell Culture-fair IIIb, Weschler Adult Intelligence Scales (WAIS), Stanford-Binet, Woodcock Johnson, Raven’s Progressive Matrices to name a few. These individual tests have different constructs and are grounded in different although perhaps related theories on human cognition and might therefore measure different things (i.e. verbal or crystallized IQ vs. performance or fluid intelligence). Some tests are better at measuring certain types of human intelligence than others, while others do not test certain types of intelligence at all. For instance, Binet IV is one of the only well-known tests to have a quantitative reasoning scale. And subsequent revisions of the same test may change the measurement focus. Individuals may score more highly in some sections of the same test, while individuals may also score more highly on one test vs another.

To make matters more complicated, several of the above-mentioned tests use the same mean score of 100 but employ a different standard deviations which makes the comparison of test scores meaningless unless these scores are adjusted for the standard deviation of the test in question resulting in the score being converted into a percentile. For instance, the standard deviation for the Woodcock-Johnson Test of Cognitive Abilities is 16. So a score of 132 (i.e. two standard deviations above the mean score of 100) would place a test taker in the top 2% of the population.  The Cattell verbal tests on the other hand, have a standard deviation of 24, which means that a score of 148 (i.e. again two standard deviations above the mean of 100) corresponds to a score in the top 2% of test takers.

Finally, IQ tests will normally have a ceiling (i.e. Cattell verbal has a ceiling for 161 for adults which corresponds to a result in the 99.48% of the population – or one in 192 people). But someone scoring 141 on the Woodcock-Johnson test would be in exactly the same percentile. This latter point makes estimating the highest IQ in the world very difficult as estimates are then required on top of the estimations and errors that are inherent in IQ testing.

Highest IQ among geniuses of history

The interest in the highest IQ is really an interest about human genius and achievement. Would anyone care about someone with an alleged IQ of 300 (assuming this was even possible to measure) if that individual were incapable of doing anything other than scoring highly on every possible intelligence test? Probably not. So looking for the highest IQ is really about identifying human genius. You don’t need a psychologist to establish that great historical figures such as Da Vinci, Mozart, Beethoven or Graham Bell were geniuses. But highly fine-tuned IQ tests were not in existence at the time to measure their IQs the same way that Al Gore is said to have tested at 134  (but was the standard deviation 15, 16 or 24?).  So again, we are within the realm of estimates on top of estimates.

I will re-visit this topic in future posts. Meanwhile, you can have your fluid intelligence tested here.

New IQ test questions

New IQ test questions for the New Year
New IQ test questions for the New Year

Happy 2014 everyone! Wishing everyone health and happiness for the year to come. Body and mind.

At, we aim to provide the most reliable culture-fair testing on the web. IQ can be decomposed into two principal components of fluid (Gf) and crystallized (Gc) IQ. As explained previously, fluid intelligence relates to your ability to solve novel problems while crystallized intelligence is more akin to an accumulated body of knowledge that is largely acquired in formal education. So if I were to ask new IQ test questions including: what do Canada, Uganda and Iraq have in common? (One plausible answer could be that they all have populations of about 35 million people), this has to do with crystallized intelligence as you would have needed to have learned and memorized what the population of each of these countries is.  On the other hand, if I ask you what to identify the new logical symbol in the following sequence: O X O X? (The most logical answer being “O”), then this has more to do with the inherent logical reasoning ability of your brain, and is thus fluid intelligence, or an ability to solve novel problems (i.e. that you probably have never seen before).

The good news is that crystallized intelligence improves with education levels, and life experience and peaks when we reach our mid-50s. Fluid intelligence on the other hand, is believed to be genetic and peaks in our mid 20s and begins a sharp decline thereafter.

Here at, we believe that fluid IQ tests are the only kinds of tests that are applicable to a global internet audience. These culture-fair tests also control for the varying levels of education attained by individual test takers. That is, unlike crystallized IQ tests, studying for a PhD should not confer any sort of advantage on fluid intelligence IQ tests, although statistics tell us that those people who go on to complete a PhD are likely to have a higher IQ than say unskilled workers  who struggled to get through high school. We strive to provide the most realistic and accurate culture-fair testing on the web. For this reason, we are constantly thinking up new IQ test questions.

So why take an IQ test and why should we seek out new IQ test questions? More often than not, the answer might be lodged somewhere between curiosity and reaffirmation. Some test takers cite challenge and intellectual challenge with bright minds seeking to join high IQ societies to find like-minded people with curious minds. Taking online IQ tests are a good way to prepare for professionally-administered IQ tests because they diminish some of the element of surprise that you might encounter on the day.

New IQ test questions for the New Year

Off the back of the success of our culture-fair IQ test, we have developed a bank of new IQ test questions for the New Year and will be offering two more fluid intelligence IQ tests during the month of January. If you haven’t already taken our first culture-fair IQ test, you can give it a go here.

Is IQ genetic?

Is IQ genetic?
Is IQ genetic?

Is IQ genetically pre-determined or is IQ formed and acquired by the environment? Scientists have long been intrigued by the origins of IQ, and in particular whether IQ is genetically inherited or whether a high IQ is the result of a stimulating environment. If IQ is in fact explained by environmental factors (i.e. nurture rather than nature) then this provides validation to millions of parents globally who would like to believe that all the time, effort and money that they are investing in creating stimulating environments for their children will pay off with higher IQs, and that greater education and smarts will help their children to do better in a competitive world. If IQ is found to be genetic however, then this calls into question the usefulness of head start programs for children and equality-driven movements that seek proportional representation of various ethnic groups in the workplace.

So is IQ genetic or environmental in origin? Several studies have helped shed light on the issue. The short answer is that genetics explain over 50% of variations in IQs, with the balance explained by environmental factors. That said, genetics are more likely to be the dominant explanatory factor and I will elaborate why. IQ or intelligence needs to be decomposed into its two principal components of (1) crystallized (Gc) vs (2) fluid intelligence (Gf) before re-visiting the question of whether IQ is genetic or environmental.

Several interesting studies have examined the IQs of adopted children, comparing these against the IQs of their adoptive parents and that of their biological parents. In their 1978 Texas adoptions study, Scarr & Weinberg measured that adopted eight year olds’ IQs had a coefficient of correlation of 0.13 (i.e. a lower coefficient of correlation than two random people off the street) with their adoptive parents, which compared to 0.32 with their birth mothers. By the age of 18, the coefficient of correlation with adoptive parents fell to 0.06 (which is virtually no relationship at all!) which compared to 0.48 with their adoptive mothers. In other words, the genetic factor became stronger as the adopted children approached adulthood. For the environment however, the correlation fell to near zero for the adopted children and their adoptive parents. Similar results were also obtained in several follow-up studies.

Is IQ genetic then? Really…

So the positive IQ effect of the home environment fades over time and genetics prevail. This give new meaning to the expression “the apple doesn’t fall far from the tree”. Counter-intuitively, crystallized IQ appears to be more heritable than fluid intelligence.

Because the explanatory power of environmental factors on IQ diminishes over time, it is for this reason that I will argue that genetics are likely to play a larger environmental factor than environment. 60% appears to be a reasonable estimate. Is IQ genetic? It would appear to be the case.

This said, it has been shown that crystallized intelligence peaks in our late 50s compared to fluid intelligence which peaks in our mid 20s. It has also been shown that crystallized intelligence correlates positively with every additional year of formal education. For this reason, creating a favourable home environment for children is highly advisable despite the importance of genetics.

Click here to take a highly accurate fluid intelligence IQ test.

Alcohol consumption and IQ

Alcohol consumption and IQ
Alcohol consumption and IQ are positively correlated

A study published in 2010 has suggested that brighter children in the UK and the US grow up to drink more alcohol. There is a very strong monotonic association between childhood intelligence (measured before the age of 16) and the frequency of alcohol consumption in their 20s, 30s and 40s. Very bright British children (with IQs > 125) grow up drinking nearly one full standard deviation more alcohol than their very dull classmates (with IQs < 75). So there is a clear association between alcohol consumption and IQ. The author concludes that in early humans, alcohol consumption would be accidental and achieved by consuming fermented fruits. So the liquid form of it can be traced back less than 10,000 years is therefore considered evolutionary novel. Because of this, it is posited that more intelligent humans would tend to seek its liquid consumption because doing so is evolutionary novel.

A recent study by the University of Illinois in Chicago also found a link between alcohol consumption and IQ, or at least cognitive function. Specifically, men who drank the equivalent of two pints of beer were found to be better at solving brain teasers and puzzles than their teetotal counterparts. The study found that men with a blood-alcohol level of 0.07% or higher solved 40% more problems than the sober control group and took 12 seconds to complete the task compared to 15.5 seconds for the sober group.  The study found that men who drank a moderate amount of alcohol performed worse in tasks involving working memory but significantly better in creative problem solving.

A third study from the London School of Economics also found that women who graduated from college were more likely to admit daily drinking.

Alcohol consumption and IQ are related. So what should you do about it?

Despite what appears to be a clear relationship between alcohol consumption and IQ, is it not clear whether drinking alcohol can increase IQ. In fact, binge drinking can have disastrous consequences on the brain that are likely to adversely affect neurological functions including IQ.

One thing is for sure, if the smartest among us tend to drink more, it is probably OK to consume moderate amounts of alcohol in the context of a healthy diet and overall lifestyle. Who knows? Your most creative moments may appear after a glass of wine or a beer (or two).

If you want to test the results yourself, you can take an IQ test here, and see whether you score improves after a beer or two. CLICK HERE


Brain training to increase IQ

Brain training to increase IQ? New synapses may form but IQ advantage is not clear
Brain training to increase IQ is still largely unproven

Brain training to increase IQ

Neuroplasticity is an umbrella term that refers to changes in neural pathways and synapses is responses to changes in behavior, environment and neural processes as well as changes resulting from injury. The neuro-scientific community had long believed that the brain was largely fixed and immutable after childhood, although recent studies have suggested that human brains remain plastic into adulthood.

The finding that adult brains continue to form new neural pathways and synapses has propelled several companies to forge into the area of brain training to increase IQ (or at least in the hope of being able to achieve this). Nintendo Wii, as well as Lumosity and a whole bunch of apps design firms have all tried to capitalize on the concept of neuroplasticity by developing brain training programmes and games that target neurological functions including memory, speed, attention and reasoning. The thinking goes that strengthening these cognitive functions could confer a wider overall cognitive benefit of increased IQ or general intelligence.

So is there any basis for believing that IQ can be improved through brain training? Well the answer is both yes and no. Brain training to improve IQ is still subject to much controversy. In support of the motion, the fact that brains remain plastic into adulthood is a good starting point. If this were not the case, we would not be having this debate.

Second, it has been shown that working memory, the mental blackboard that enables us to both retain and manipulate information, is strongly correlated with fluid intelligence (the component of intelligence which is largely believed to be innate and relating to our ability to solve novel problems). In particular, a 2008 study by Susanne Jaeggi found that brain training to increase IQ was possible by training working memory via a simple exercise called dual-n back. She found that people who increased their n-back scores also improved their scores on fluid intelligence tests such as Raven’s Progressive Matrices (RPM) or IQ tests found here. However, subsequent studies failed to replicate Jaeggi’s results. So the support in favour of the camp yes camp may be weaker than initially thought.

Brain training to increase IQ requires further investigation

The reality is that most of us will be able to increase our performance on some of these individual tasks and games, but it has yet to be convincingly demonstrated that getting better at a particular task will confer wider benefits of increased overall intelligence or IQ.

That said, a few other studies have shown that brain training can improve speed and memory. Speed and memory are vital to achieving a high score on an IQ test. For instance, Mensa-administered Catell culture-fair tests are timed tests, with about 50 questions to answer in less than 15 minutes. So improving one’s speed is likely to enable the test taker to cover more questions and perhaps to take an educated guess rather than guessing blind.

We will revisit this topic in future posts. Meanwhile, you can test your fluid intelligence here.

Child prodigies

Child prodigies include young Mozart
Mozart is among the most famous child prodigies

Child prodigies are children with exceptional talents which are recognized at a very young age. These children are usually more than just academically bright, they possess talents and abilities that are far beyond their years. Usually, child prodigies will also have a very high IQ. It is important to remember that IQs vary over time. Fluid intelligence peaks in our mid 20s and begin to decline afterwards. Crystallized intelligence on the other hand, peaks in our mid 50s due to the greater body of accumulated knowledge and experiences in people of that age. Well-conceived IQ tests should therefore measure IQs relative to people in your own age group. In its beginnings, IQ testing involved measuring someone’s mental age (MA) and dividing by that person’s chronological age (CA). A child that was able to perform that’s in excess of his or he chronological age (or actual age) was then considered to be smart for his or her age, and a high score could be associated with child prodigies. The greater the distance between MA and CA, the higher that person’s IQ would be. So in modern-day IQ testing, a child who takes the same IQ test as an adult may achieve the same lower number of correct answers than the adult, but still have a much higher IQ than the adult. The real way to establish the distribution of IQ test results for say, eight-year-olds taking a particular test, is to test a large representative sample of eight year olds, and to establish a distribution of those results for that particular test. So the average score on the test for the eight year olds may be 40% correct, with a standard deviation of 5 percentage points. If this were to be the case, roughly 68% of kids would have gotten a score between 35 and 45% correct. So the eight year old child in the top 2% would have answer 55% of questions correctly.

If you were to administer this exact test to 25 year old adults, the average for the adults might be 55%, with a standard deviation of 5%. So an adult in the top 2% of 25 year olds would need to answer 65% of questions correctly.

So the 8 year old answering 55% of questions correctly would have a higher IQ (in the top 2%) than the 25 year old who answered 60% of questions correctly (top 32% of test takers). So bright children may not be smarter than adults in absolute terms, but are definitely so in relative terms.

Examples of child prodigies

Some famous child prodigies include Mozart (IQ of 143), would was writing concertos by the age of 8. Bobby Fischer (IQ of 160) was a young chess champion, while Terrence Tao (IQ>200) was the youngest-ever winner of field medals in mathematics. So being a child prodigy is not just about high IQ, it’s about incredible accomplishment for that child’s age.

For more information about IQ, click here.

IQ boosting foods

Gotu Kola: is it really on the list of IQ boosting foods for healthy adults?
IQ boosting foods may include Gotu Kola supplements for children with mental retardation

Diet most definitely plays a part in improving or maintaining your IQ. There are plenty of foods which are reported to enhance mental alertness and even possibly enhance IQ. So you not only need to consider your waist line when it comes to diet, but you also need to consider the impact of what you eat on your brain and your mental processing abilities.

Let’s look at a list of possible IQ boosting foods. We will attempt to categorize them into moderately high evidence, medium evidence and low evidence of possible effects on the brain.

Moderately high evidence

  1. Creatine: often used by bodybuilders, creatine is a nitrogenous organic acid that occurs naturally in vertebrates and helps supply energy to all cells in the human body. An Australian study found that creatine supplementation in the short term provided a significant boost in brain power including memory. Refinements on this study found that creatine supplementation was able to negative the negative effects of sleep deprivation.
  2. Omega and fish oils: supplementation by either pregnant mothers or to young infants has been shown to increase IQs of children by up to 3.5 points. A study in northern England also found that pupil performance improved with fish oil supplementation. Some studies have also found that consumption of fish oils conferred an IQ advantage in adults. Although omega and fish oils are IQ boosting foods, the purity of the oils is also a critical component.

Medium-evidence IQ boosting foods

  1. Gotu Kola: is a pervasive south Asian herb. Its supplementation has been shown to improve IQs of children with mental retardation by up to 10%. It is not clear whether this herb can achieve the same feet in normal children or adults.
  2. Blueberries: some studies have found that their consumption may improve memory in older adults with age-related memory problems. Berries contain flavonoids have recently been found to confer positive benefits to the brain. Whether or not blueberries are really an IQ boosting food remains unknown, but these tasty foods certainly fall in the category of super foods and are thus worth adding to one’s diet.

Low-evidence IQ boosting foods

  1. Gingko Biloba: is a herb that has long been claimed to boost memory and concentration. Although the strongest early evidence in its favor related to the treatment of Alzheimer’s, recent meta analyses have suggested that the herb does not alter the progression of the diseases and that memory or problem-solving abilities are not enhanced by its consumption. This one should really fall off the list of IQ boosting foods.

You may want to test your baseline IQ here, and to re-test once you have added these elements to your diet.