IQ : Intelligence Quotient

It is a number used to express how intelligent a person is.

In 1905, psychologists Alfred Binet and Theodore Simon designed a test for children who were struggling in school in France.

Designed to determine which children required individualized attention, their method formed the basis of the IQ test.

The intelligence quotient is one of the many tests of intelligence to calculate the relative intelligence of a person.

The relative intelligence of a person can be calculated from two data:

  • Mental Age
  • Chronological Age

Now, if Mental Age and Chronological Age are given to us, there is a theoretical formula to calculate a person's IQ.

Intelligence Quotient Formula:

Also, from the formula of IQ, it follows that

And

Where MA = Mental Age
CA = Chronological Age
Psychologists make classifications according to IQ range.
According to the Sandford-Binet Fifth Edition classification, the IQ level chart is below.

IQ Level Chart:

IQ Range IQ Classification
144 and above Very gifted or highly advanced
130-144 Gifted or very advanced
120-129 Superior
110-119 High average
90-109 Average
80-89 Low Average
70-79 Borderline impaired or delayed
55-69 Mildly impaired or delayed
40-54 Moderately impaired or delayed
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