IQ questions and answers

What is IQ?

1. IQ is an acronym for “Intelligence Quotient”. In the past, IQ used to be calculated as a person’s Mental Age (MA) divided by that person’s Chronological Age (CA). So a child with advanced mental processing capabilities (i.e. MA) for his/her age (i.e. CA) would be classified as having a high IQ. Although the calculation of IQ scores no longer use ‘quotients’, the term IQ is still widely used today. IQ attempts to summarise an individual’s intellectual abilities into a single score. However, there are many different types of intelligence, which is why IQ tests attempt to measure several important facets of human intelligence including (1) fluid intelligence and (2) crystallized intelligence, both of which can be further decomposed into several aspects including inter alia, verbal processing, visual processing, short term memory, long term memory and processing speed. All of these facets of intelligence are usually distilled into a single global score which is known as ‘G’ or ‘Spearman’s G’. Think of G as a global composite (or a weighted average) of your performance on individual aspects of the IQ test.

Normal IQ

2. It’s all relative. Normal IQ is ascertained relative to the average IQ within a given population. In most modern¬† societies, the average IQ has been set to 100, and depending on the test taken, the standard deviation (or dispersion) or results can either be 15, 16 or 24 points. Statistical rules tell us that about 68% of the population will score within one standard deviation of the test average. So if the standard deviation of the test in question is 16 points, we know that 68% of the population will score between 84 and 116. But based on the distribution of IQs however (and assuming a standard deviation of 16), psychologist normaly agree that an IQ of between 90 and 109 to be average.
About 47% of the population will score within this range. So if you have an IQ score which is lower than 90 but higher than 80, you will be considered to have a ‘low average’ IQ. If on the other hand you score between 110-119, you are considered to have a high average IQ. But normal IQ is all about understanding the average IQ within a given population or environment. If you are a member of Mensa, it would be normal for people around you to have a high IQ in the 132+ range (again assuming a 16 point standard deviation). So within the realms of a high IQ society such as Mensa, an IQ of 100 is not possible, let alone normal.

How accurate is IQ?

3. It is not perfect but it is good. There are various components to intelligence. The simplest (and well-supported) g factor analysis is the Cattel-Horn theory of intelligence which breaks down Spearman’s g into: (1) fluid intelligence -gf; and (2) crystallised intelligence -gc. It is important to remember that IQ does not measure things like aptitudes, creativity or general motivation. Rather, IQ (and in particular fluid intelligence) is almost analogous to raw processing power of the brain,

How accurate are IQ tests?

4. Any test or model cannot be 100% accurate in terms of measuring anything at all. For instance, when you go to your GP/Doctor for a general check-up, the doctor has limited time and will carry out a number of tests (e.g. heart rate, blood pressure, temperature and perhaps blood tests) to help establish whether you are healthy. Your doctor cannot afford to spend 48 hours with you to observe your physical condition and vitals across a variety of settings (nor would you want to be followed around by your doctor!).

Similarly, exam finals in school attempt to test your understanding of the key concepts that you will have learned throughout the year, rather than testing every single piece of knowledge that you have on the subject matter (which would not be possible in a 90 minute exam).

IQ tests similarly attempt to measure general intelligence in a short space of time. Some tests are better than others at measuring certain aspects of intelligence (e.g. Culture-fair testing are fairly good at measuring fluid intelligence). You should not know the content of an IQ test before you take it (and hence the concept of solving novel problems). So in theory, all test takers are faced with the same element of surprise and the test should therefore capture differential abilities of the test takers at solving novel problems (therefore measuring fluid intelligence).

Are IQ tests biased?

5. IQ tests as we know them today were born in the late 1890s and the modern-day relatives of those pioneering tests have come a long way in addressing obvious flaws in the testing procedures. The widespread used of several well-adapted IQ tests have yielded millions of test observations, which have been available for the statistical validation of IQ as a robust measure of general intelligence. Culture-fair tests do not require any spoken language (other than understanding simple instructions at the outset of the test) and therefore eliminate many possible cultural and gender biases.

High IQ

6. The mean (average) level of IQ for most developed nations is about 100 (the global mean is about 90 due to the inclusion of poor nations. which drag down the mean IQ – Google search: “IQ and the Wealth of Nations” for more on this topic ). In developed nations (and assuming a 16 point standard deviation), an IQ falling within the band of 90-109 is considered average. An IQ falling between 110-119 is considered a high average, whilst IQs > 120 are considered superior. About 3% of the population have an IQ of 130+, while Mensa accepts testers who are in the top 2% of the population (implying a score of 132 with 16 SD).

Although an IQ in the top 2% appears to be very select at first glance, the group is not that exclusive when you consider that roughly 20 million Chinese have this level of intellect (i.e. 2% of 1 Billion population). This Mensan Chinese would therefore be able to fill all the student seats at Harvard 952 times over.

Types of IQ tests

7. There are several types of IQ tests. In simple terms, the two most prevalent types of tests are (1) Crystallized / verbal intelligence tests and (2) fluid intelligence or performance IQ tests. Crystallized intelligence tests measure cognitive abilities that tend to improve with education levels achieved. For instance, verbal intelligence IQ tests will ask questions about the meaning of words, synonyms and antonyms, and general comprehension. The issue with these types of tests is that they will favour individuals with high levels of education.

Fluid intelligence tests, on the other hand, are more akin to measuring the raw processing power of the brain. If well constructed, these tests do not favour individuals with higher education and can thus be classified as being culturally-fair. Culture-fair tests (in particular Cattell IIIa or Raven’s Progressive Matrices) are widely supported in academic and professional circles. They are also widely accepted as cognitive ability tests for admission into several high IQ societies. Mensa accepts, inter alia, both the Cattell IIIa test and RPM, whereas the Tripe Nine Society (a society for the 99.9% percentile) accepts the Cattell Test as one the the allowable tests for admission.

Can you raise your IQ?

8. Is it much more difficult to raise your inteligence than it is to raise your IQ score. You will be able to raise your IQ score by practising the types of questions that may appear on these tests. Our culture fair test aims to replicate the level of difficulty and time pressure that you would face on a Mensa-administered Cattell IIIa test. This may help eliminate some of the surprise element that you would experience on the proctor-administered test. IQ-Brain.com tests are essential practice for the real life test.
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