IQ means Intelligence quotient, a factor that measures people's intelligence based on the results of specific tests. IQ measures an individual's cognitive performance compared to people in the same age group.
The first test to measure intellectual ability was developed in the early 20th century by the French psychologist Alfred Binet (1859-1911). Initially, the test was applied only in schools to identify students with learning difficulties.
Later, the German psychologist William Stern (1871-1938) created the expression Intelligence Quotient, introducing the terms "IM (Mental Age)" and "CI (Chronological Age)" to relate a person's intellectual capacity to their age.
Intelligence scales were proposed by psychologist Lewis Madison Terman (1877-1956), based on several works on gifted children. Using the formula IQ = 100 x IM / CI, he classified results above 140 as genius and values below 70 as slow thinking.
Based on new studies, David Wechsler (1896-1981) created a test developed exclusively for adults, defining the Wechsler Intelligence Scale for Adults (WAIS -
Wechsler Adult Intelligence Scale), which has already undergone revisions.Intelligence levels are ranked based on the test result, according to the scale:
130 or greater: Giftedness
120 - 129: Superior intelligence
110 - 119: Above average intelligence
90 - 109: Average Intelligence
80 - 89: Weak Normal
70 - 79: Limit of disability
Equal to or less than 69 - Mentally handicapped
See too:
- Types of intelligence
- Intelligence