Classification of People on the Basis of I.Q

Intelligence Quotient

A total score obtained from one of the many standardized tests created to evaluate human intelligence is known as an intelligence quotient (IQ). The psychologist William Stern created the abbreviation "IQ" for the German term Intelligenzquotient, which he used to describe the scoring system for intelligence tests that he promoted in a book published in 1912. Although this was not always the case historically, the median raw score of the norming sample is now defined as IQ 100 and scores each standard deviation (SD) up or down are defined as 15 IQ points more or less. According to this criteria, around two-thirds of the population has an IQ between 85 and 115. Approximately 5% of people have scores above 125 and 5% have scores below 75.

Classification of people on the basis of I.Q

There have been various classification systems for IQ.

Terman's classification was:

Later, Wechsler thought that it would be much more legitimate to base his classifications on the Probable Error (PE) so his classification was:

These terms are now mostly out of date, and mental retardation is now the norm instead of mental deficiency. The classification of retardation in use right now in the USA is as follows:

Additionally, "trainable" mentally retarded is generally akin to moderate mental retardation, while "educable" mentally retarded is similar to mild. The DSM now adds an extra requirement for a person to be classified as retarded: an evaluation of their adaptive functioning. IQ is insufficient. Perhaps calling someone a genius should follow the same pattern.