Intelligence Quotient - What is a normal IQ Range?

IQ or Intelligence Quotient is an indicator of a person’s intellectual capacity. How is it calculated? What is a normal Intelligence Quotient?

Definition: The Intelligence quotient defines a series of psychometric tests of mental efficiency and obtaining responses at that test. Contrary to popular belief, Intelligence Quotient doesn`t calculate person`s intelligence, but establishes an average value between your capacity and population reference. Some specialists have formed an opinion that IQ depends on person’s genetics; of course, it depends on the environment as well.

Historical background: Though the term “Mental Test” had already been used in 1890 by the American psychologist Raymond Bernard Catell, it was only in 1906 that the first tests were developed by Frenchman Alfred Binet for the Ministry of National Education. His main purpose was to identify children who did not study well and to calculate their age mentality. Binet`s test has been modified over the time and has been tangibly improved. For example many people divided the test results on the true age of the child and then multiplied it on 100; each coming up with his or her own interpretations of the test.

Different types of IQ: There are different types of Intelligence Quotient, elaborated by different researchers with different scales (classifications): each person`s mental age correspond – the classical IQ test; others are based on averages obtained from a reference population – the distributive IQ test. In general the classical IQ test; is used for children, because the mental age doesn`t mean that much for adults. For adults the standard Wechsler IQ test is used. The obtained answers depend at person at that person is supposed. For example, the IQ score of 150 points by Wechsler scale is equal to 180 points by Catell scale.

Numbers: The Intelligence Quotient includes points from 0 to 200. The average rate is approximately 100 points. The lower limit is normally 80 points and the upper limit is 140 points. For your information, Albert Einstein`s IQ response was 160 units, and after the work he has done it is assumed that Descartes response – 185 units.

The development of the Intelligence Quotient runs till the age of 6 – 7 years, after that it isn’t a subject to further changes. Your response will be the same either when you’re 20 years or 40 years old. Nevertheless, if the person is sick, depressed or has some other problems, the Intelligence Quotient may decrease.

Tests: The principle is to answer a series of questions, to complete a questionnaire with multiple answer variants or to comment on the results in the presence of a psychologist. The questions refer to linguistics, logic and memory and they are divided into thematic sections. The results (speed, accuracy, etc…) of the test are compared to the results of the reference population. There is a possibility to time the test.

Prices for such kind of tests do differ from paid services offered by some offices to free tests lead by a psychologist for the school children.

Limits: The Intelligence Quotient is an indirect measurement that classifies a person if compared to the reference population’s rate.

So the given evaluation cannot be deemed the ideal one. Psychologists and other experts estimate that the reliability of such a test is 70%. On the other part, these tests don`t take into consideration such aspects as person’s imagination and creative abilities.