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.
The relative intelligence of a person can be calculated from two data:
Now, if Mental Age and Chronological Age are given to us, there is a theoretical formula to calculate a person's IQ.
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 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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