The concept of "intelligence quotient" was introduced by the German psychologist William Stern. He used IQ as an acronym for the term Intelligenz-Quotient - mental development coefficient . IQ was a score obtained from a series of standardized tests conducted under the guidance of a psychologist in order to determine the level of intelligence.
Mind Research Pioneers
Initially, psychologists doubted that the human mind could be measured, all the more accurately. While there has been interest in measuring intelligence for thousands of years, the first IQ test has only recently appeared. In 1904, the French government asked psychologist Alfred Binet to help identify which students are most likely to have difficulty at school. The need to establish the intelligence of schoolchildren arose so that all of them could receive compulsory primary education. Binet asked Theodore Simon’s colleague to help him create a test that focuses on practical issues: memory, attention and problem solving — things that children are not taught in school. Some answered more complex questions than their age group, and therefore, based on observational data, the now classic concept of mental age has appeared. The result of the work of psychologists - the Binet - Simon scale - was the first standardized IQ test.
By 1916, Stanford University psychologist Lewis Terman had adapted the Binet – Simon scale for use in the United States. The modified test was called the Stanford-Binet Intelligence Scale and has become the standard intelligence test in the United States for several decades. At Stanford Bean, a number known as IQ is used to represent an individual result.
How to calculate intelligence?
IQ was initially determined by dividing the mental age of the person who passed the test by its chronological age and multiplying the quotient by 100. It goes without saying that this works (or is best suited) only for children. For example, a child with a mental age of 13.2 years and a chronological age of 10 years has IQ 132 and has the right to join Mensa (13.2 Ă· 10 x 100 = 132).
During the First World War, several tests were developed in the United States Army to select recruits suitable for specific jobs. The Alpha Army test was written, and Beta was conducted for illiterate recruits.
This and other IQ tests have also been used to test new immigrants arriving in the United States from Ellis Island. Their results were used to fabricate false generalizations about the “surprisingly low intelligence” of immigrants from southern Europe and Jews. These results in 1920 led to the proposals of the "racially motivated" psychologist Goddard and others to Congress to introduce restrictions on immigration. Although the tests were conducted only in English, and the vast majority of immigrants did not understand him, the United States government deported many thousands of worthy people who were labeled as “unsuitable” or “unwanted”. And this happened a decade before in Nazi Germany they started talking about eugenics.
Psychologist David Wexler was unhappy, in his opinion, with the limited Stanford-Binet tests. The main reason for this was the only assessment, its emphasis on time limits, and the fact that the test was designed specifically for children and therefore was not suitable for adults. As a result, during the 1930s, Wexler developed a new test, which was known as the Wechsler Intelligence Scale - Bellevue. Subsequently, the test was revised and became known as the Wechsler Intelligence Scale for Adults, or WAIS. Instead of a single overall assessment, the test created an overall picture of the subject's strengths and weaknesses. One of the advantages of this approach is that it also provides useful information. For example, high scores in some areas and low in others indicate the presence of specific learning disabilities.
WAIS was the first test by psychologist Robert Wexler, and WISC (Wexler Intelligence Scale for Children) and Wexler Preschool Intelligence Scale (WPPSI) were developed later. The adult version has since been revised three times: WAIS-R (1981), WAIS III (1997) and in 2008 WAIS-IV.
Unlike tests based on chronological and mental age scales and standards, as in the case of Stanford-Binet, all versions of WAIS are calculated by comparing the result of the test person with data from other subjects of the same age group. The average IQ score (worldwide) is 100 points with 2/3 of the results in the “normal” range from 85 to 115. WAIS standards have become the standard in IQ testing, and therefore they are used by the Eysenck and Stanford-Binet test, except that the standard deviation in it is not 15, but 16. In the Kettell test, the deviation is 23.8 - it often gives very flattering IQs, which can mislead uninformed people.
High IQ - High Intelligence?
The intelligence coefficient for the gifted is determined using special tests that provide psychologists with a lot of useful information. For many of them, the average score is fixed at 145-150, and the full range is between 120 and 190. The test is not designed for results below 120, and more than 190 points are very difficult to interpolate, although this is possible.
Paul Kojmans from the Netherlands is considered the founder of IQ tests of the upper range, and he is the creator of most of the original, and now classic, tests of this type. He also founded and administers super-high IQ societies: Glia, Giga, and Grail. Among the most famous and popular Coymans tests are the “Test for Genius”, “Nemesis Test” and “Coymans Multiple Choice Test”. Paula's presence, influence, and participation are indispensable conditions, an integral part of the spirit of ultra-high IQ tests and its communities as a whole. Other classic high intelligence test gurus are Ron Hoeflin, Robert Lato, Laurent Dubois, Mislav the Betrayer and Jonathon Wye.
There are various types of thinking that manifest themselves in different ways at different levels. People have different skills and level of intelligence: verbal, typical, spatial, conceptual, mathematical. But there are also various ways of their manifestation - logical, lateral, convergent, linear, divergent and even inspired and ingenious.
Standard and advanced IQ tests reveal a common intelligence factor; but in high-level tests, it is determined in various ways.
People often talk about high IQ scores that are called IQ geniuses, but what do these numbers really mean and how do they add up? Which IQ score is a sign of genius?
- A high IQ is any score above 140.
- Genius IQ - over 160.
- Great genius - score is equal to or greater than 200 points.
High IQ is directly related to academic success, but does it affect success in life in general? How much more successful are geniuses with lower IQ? Some experts believe that, compared to other factors, including emotional intelligence, IQ is less important.
IQ Breakdown
So how exactly are IQ scores interpreted? The average IQ test score is 100. 68% of the IQ test results fall within the standard deviation from the average. This means that for most people, the IQ is between 85 and 115.
- Up to 24 points: deep dementia.
- 25–39 points: severe mental disability.
- 40–54 points: moderate dementia.
- 55–69 points: mild mental disability.
- 70–84 points: borderline mental disorder.
- 85–114 points: medium intelligence.
- 115–129 points: above average.
- 130–144 points: moderate giftedness.
- 145–159 points: high giftedness.
- 160–179 points: exceptional giftedness.
- over 179 points: deep giftedness.
What does IQ mean?
When talking about intelligence tests, IQs are called “gifted points”. What do they represent when assessing IQ? To understand this, it is important first of all to understand the testing as a whole.
Today's IQ tests are based mainly on original tests developed in the early 1900s by French psychologist Alfred Binet to identify students who need additional help.
Based on his research, Binet developed the concept of mental age. Children of some age groups quickly answered questions that were usually answered by older children — their mental age exceeded the chronological. Binet’s intelligence measurements were based on the average abilities of children of a certain age group.
IQ tests are designed to measure a person’s ability to solve problems and reason. Assessment of the IQ is a measure of moving and crystallized mental abilities. The scores show how well the test was passed compared to other people in this age group.
Understanding IQ
The distribution of IQ estimates corresponds to the Bell curve, a bell-shaped curve whose peak corresponds to the largest number of test results. The bell then drops on each side - on one side there are points below the average, and on the other above.
The average value in this case is equal to the average score and is calculated by adding all the results, followed by dividing them by the total number of points.
Standard deviation is a measure of variability in a population. A low standard deviation means that most data points are very close to the same value. A high standard deviation indicates that data points are generally far from the average. In IQ testing, the standard deviation is 15.
IQ is increasing
With each generation, IQ increases. This phenomenon is called the Flynn effect, named after researcher Jim Flynn. Since the 1930s, when standardized tests became widespread, researchers have noted a steady and significant increase in assessments of test results in people around the world. Flynn suggested that this increase is due to the improvement of our ability to solve problems, think abstractly and use logic.
According to Flynn, past generations mainly dealt with specific and specific problems of their immediate environment, and modern people think more about abstract and hypothetical situations. Not only that, but also approaches to learning over the past 75 years have changed dramatically, and more people are usually engaged in mental work.
What do tests measure?
IQ tests evaluate logic, spatial imagination, verbal-logical thinking, and visual abilities. They are not intended to determine knowledge in specific subject areas, since the intelligence test is not something that can be learned in order to improve your score. Instead, these tests evaluate the ability to use logic to solve problems, recognize patterns, and quickly establish relationships between different information.
Although it is often heard that prominent personalities such as Albert Einstein and Stephen Hawking have an IQ of 160 or higher, or some presidential candidates have specific IQs, these numbers are merely estimates. In most cases, there is no evidence that these famous individuals have ever passed the standardized IQ test and, moreover, made its results public.
Why is the average score equal to 100?
Psychometrists use a process known as standardization to compare and interpret IQ scores. This process is carried out by conducting a test on a representative sample using its results to create standards or norms by which individual assessments can be compared. Since the average score is 100, specialists can quickly compare individual scores with the average to determine if they fall into the normal distribution.
Classification systems can vary from one publisher to another, although many tend to follow one rating system. For example, on the adult intelligence scale of Wexler and in the Stanford – Binet test, scores in the range of 85–115 are considered “average”.
What exactly do the tests evaluate?
Tests for determining the coefficient of intelligence are designed to assess crystallized and moving mental abilities. Crystallized includes knowledge and skills acquired throughout life, and moving - includes the ability to reason, solve problems and comprehend abstract information.
Moving intelligence is considered independent of learning and tends to decline in more mature age. Crystallized is directly related to learning and experience and is constantly increasing with time.
An intelligence test is conducted by licensed psychologists. There are different types of tests, many of them include a series of subtests designed to assess mathematical abilities, language skills, memory, reasoning skills and information processing speed. Their results are then combined to form an overall IQ score.
It is important to note that, although they often speak of medium, low, and brilliant IQs, there is no single test for intelligence. Today, many different tests are used, including Stanford - Binet, Wexler adult intelligence scale , Eisenck test and Woodcock - Johnson cognitive tests. Each of them differs in that it is precisely how it is evaluated and how the results are interpreted.
What is considered low IQ?
An IQ equal to or lower than 70 points is considered low. In the past, such an IQ was considered the benchmark for mental retardation, intellectual disability, characterized by significant cognitive impairment.
Today, however, IQ alone is not used to diagnose intellectual disability. Instead, the criterion for this diagnosis is a low IQ with evidence that these cognitive limitations existed before the age of 18 and related to two or more adaptive areas, such as communication and self-help.
About 2.2% of all people have an IQ score below 70.
So what does it mean to have an average IQ?
An IQ level may be a good general indicator of the ability to reason and solve problems, but many psychologists suggest that tests do not reveal the whole truth.
Among the few things that they are not able to measure are practical skills and talents. A person with an average IQ can be a great musician, artist, singer, or mechanic. Psychologist Howard Gardner developed a theory of multiple intelligence designed to address this shortcoming.
In addition, the researchers found that IQ may change over time. A study of the intelligence of adolescents with a gap of 4 years yielded results, the values ​​of which varied by 20 points.
IQ tests also do not concern the assessment of curiosity and how well a person understands and owns emotions. Some experts, including writer Daniel Goleman, suggest that emotional intelligence (EQ) may be even more important than IQ. Researchers have found that high IQ can really help people in many areas of life, but it does not guarantee life success.
So worry about the lack of genius is not worth it, since the vast majority of people are not geniuses. Just as a high IQ does not guarantee success, a medium or low IQ does not guarantee failure or mediocrity. Other factors, such as hard work, perseverance, perseverance, and general attitude are important parts of the puzzle.