IQ Classification: How do I interpret an Intellectual Quotient score?

The Intellectual Quotient (IQ) is the unit of measurement of intellectual aptitudes assessed by psychometric testing. It is generally used to measure cognitive functioning a person in the context of a psychological assessment. Pass one IQ test is done in a controlled manner, with a specialist psychologist HIP. This psychometric assessment is generally planned in two situations: (1) in children and adolescents who appear to be early students and/or have school difficulties (2) in adults with unusual intellectual maturity (Surpassed adult, Asperger, etc.).

In the first case, this assessment of intelligence will allow to put words on the possible ills of the child. An intellectually early child will often feel out of step with others or show a great deal hypersensitivity. Being Gifted is not always easy, and making the right diagnosis to enable him to understand the potential is a first step. I know what I'm talking about: understanding what was going on in my head finally allowed me to put a word on what I felt. Be careful, however: douance does not always mean boredom, school failure or class jump. Every situation is different. In the case of gifted adults, taking different IQ tests allows to identifying potential (if there is potential) and to help this extraordinary intelligence flourish. Conversely, psychometry can be used to detect mental retardation.

IQ Classification Table

Historically, IQ by mental age has been calculated to detectchildren to High Intellectual Potentialand those with potential difficulties. The aim was therefore to measure the intellectual abilities of only one child and/or adolescent within the school system. Gradually, the desire to test the entire population developed, and the IQ tests achievable on adults appeared with the IQ calculation method by rank. The idea is to say that intelligences are distributed according to the normal law ( Gauss curve). Wechsler's scale (the best known) sets an average intelligence of 100 and a standard deviation of 15. If you are interested in the history of IQ creation, I strongly recommend reading my article on the subject (the first link at the top of this page).

Why classify an intellectual quotient?

The IQ classification was therefore made from the moment the intelligence tests were created. Their primary goal was to divide students into three categories: "good", "means", and "bad". Later, following the principles of eugenics and the creation of a "higher race", it is therefore quite logical that some wanted to identify a higher intelligence or an early genius among the entire population. The starting point of the intellectual quotient ranking was therefore to spot the tulips in the middle of the manure – or at least to give a score from which one was classified as a tulip and not manure. It's great, good atmosphere.

Today, political correctness and advances in psychology have allowed us to change our discourses but above all to realize that people with high potential were, of course, smarter, but that they had a completely different intellectual functioning. The interest of early discovery of a zebra is therefore to help it understand its cognitive functioning to help it grow. It is, in my view, a much more noble quest than before (even if the classification remains the same).

Comparison of the different classification scales of Human Intelligence

Since then, many IQ measurement scales have emerged. In fact, everyone wanted to put their stone in the building to remedy some objections made at the scale of the moment. For example, some verbal tests (or rather subtests) made the notion of verbal IQ related to the language in which the test was conducted. As a result, the overall score could vary depending on our mastery of the country's culture. However, our intellectual ability remained the same. Or, the cognitive abilities of a psychometric assessment are assessed by psychologists who have a great deal of flexibility in assigning final scores. One can therefore rightly wonder whether these results will not vary too much depending on the familiarity of the professional with the assessment of intelligence.

In short, a lot of problems have led to many scales. However, they have one thing in common: they allow one to sit on the continuum between a lower intelligence and a great intelligence. So I put you together in the infographic next to the entire IQ classification based on scales. It is quite clear how important it is to always specify the scale to which we refer. For example, an IQ of 75 on the Cattell scale will be at the lower limit of the average intelligence, on a scale of Wechsler (WAIS or WISC) or K.ABC would be practically on mental retardation, and on the Stanford-Binet scale one is in the middle of the weak intelligence.

Interpretation of the result of the intellectual quotient test

Once you have finished your psychometric test, you will get an overall score (your intellectual quotient) which is actually composed of the results of several subtests (logical reason, speed of treatment, verbal test, etc.). If the subtest scores are close enough, they say you have homogeneous results. If one (or two) is abnormally low/high, you are said to have heterogeneous results. The overall interpretation of the results as well as of each subtest must be done with the psychologist with whom you have passed the IQ test.

Nevertheless, I will develop the classification of IQ a little, and in particular the main categories – high potential, medium intelligence and mental retardation. I took the decision not to talk about "intermediate bands" (higher and weak intelligence). Indeed, I see them rather as buffer zones that allow us to pass from theMedium intelligence in the category above or below. In addition, I think some intellectual skills are specific to high potential or mental retardation. Buffer zones are only spaces in which certain characteristics are acquired. They do not, in my view, have specific attributes. Again, that's just my opinion.

High potential or gifted IQ

High potentials – or gifted, or zebras – are individuals whose IQ is at least greater than two standard deviations from the average. At Wechsler (the best known) this would mean that you obtained a WAIS or WISC result of at least 130 (standard deviation of 15, average to 100). At Cattell, this would be from 148 (standard deviation of 24, average to 100). If you are not fluent with the concept of standard deviation, I invite you to read my general article on IQ (link at the top of this page).

Cognitive functioning induced by a gifted IQ usually results in a sense of lag, hypersensitivity, and the development of a strong emotional intelligence. The speed of treatment of external and cognitive stimuli "offer" to the individual with an unusual personality. I'm in this category myself. My therapist was detected as a zebra a few years ago, and I try through this site to understand the different implications of a high potential on my little life.

Average intelligence

Average intelligence (I don't like this term too much) actually means intelligence that most of the population should whether the IQ distribution curve followed the normal Gauss curve. Keep in mind that this is a sort of agreement between scientists, but that no specific study confirms that human intelligence is distributed according to the normal law of Gauss. So far, it has been agreed that the average value is 100, and that as a result (always according to Gauss), 68% of the population must have an intellectual quotient with more or less a standard deviation from the average. Add another standard deviation and you have the first buffer zone (low or higher intelligence), then the next standard deviation indicates the beginning of mental retardation or high potential. Below is the graphic representation of the Gauss curve on the Wechsler and Cattell scales.

These IQ classifications are in fact arbitrarily designed according to the assumption of normal intelligence distribution. On the infographic above, you will notice that the classification is symmetrical above and below the average of 100. It is also (in part) this absence of studies on the subject and the fact that everything is done and said by agreement which often makes me question the relevance of IQ tests.

In all cases, people in this category are "just" normal. Or at least, in the sense that the people who created these scales wanted to give. They are among the 68% of the average population with a very similar score.

Mental retardation

Mental retardation is an incomplete development of cognitive abilities, verbal intelligence, and/or other forms of intelligence of an individual. I am not going to go into the details of this category because this is not the theme of this site. If you want more information on the subject, I will redirect you to an excellent article in INSHEA (bottom of the page) in which you will find everything you need.

The Most High Intellectual Quotient, or THQI

I finish this part of the IQ classification with some details on the THQI (Very High Intellectual Quotient). This is a category that I have crossed a few times in my research and which would still be a standard deviation above high potential (so from 145 at Wechsler, or 172 at Cattell for example). I chose not to represent her on the infographic for several reasons. The first is that, as explained, it is not present everywhere. However, I wanted to make a concise summary which is more or less applicable on each scale (to allow comparison). The second is that she doesn't have her own when the intellectual quotient drops. Indeed, I did not find a "TBQI" ("Very Low Intellectual Quotient"). Why? I don't know.

In all cases, THQI appears to have the same characteristics as high potential, but more exacerbated. I explain: the social gap is even more evident; hypersensitivity is more present and affute; the higher emotional quotient; etc. The intellectual efficiency of these people would be incredible. As with the gifted IQ, testing the potential as soon as possible can only be beneficial because these psychometric qualities require special support (in the same way as mental retardation requires different follow-up).

Conclusion on IQ Classification

In conclusion, the IQ is classified within a continuum that ranges from high potential to mental retardation, to medium intelligence. Depending on the scale taken into account, you will find some other categories within this continuum that allow the transition between medium intelligence and high potential.

I would also like to point out that these limits between the categories have been established following acceptance of Arbitrary the distribution of human intellectual quotients according to the normal law of Gauss.

Sources

• INSHEA,Definition and origin of mental retardation.