What is IQ?

posted on 10 Jun 2015 00:25 by piquanttroupe7059
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 fluid intelligence and 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

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 normally 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 Test your IQ at IQ Brain 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.