Galyuton, known in his time as a mathematician, journalist, criminologist. However, his assumption that intelligence is dependent on the speed, accuracy and ability perception is false. At the end of the last century French scientist A. Binet also engaged in the measurement of intelligence. Impelled him to this purely practical task: the French minister of education has entrusted him to create a method by which it might be an early aged children to recognize the mentally retarded, to train them in institutions.

Binet and Simon, his assistant gave the study of this problem for 10 years. They chose a different path than Galton, and he was right. Binet and Simon analizirovali tasks that children receive from teachers, also proposed its own, covering a variety of industries related to thinking, which, respectively, the solution was evaluated. In 1905, established the first scale to assess the level of intelligence. Then it was repeatedly altered, in particular, an American scientist L. Terman of Stanford University in California. Stanford-Binet test, along with other uses and now. Binet IQ Test was standardized.

This means that each individual test result is influenced by the average assessment in general. The practice has helped to place the job in such a manner as to their complexity was on the increase and that 50% of the respondents were not could solve more than half of the proposed tasks. After processing the results of the test, each subject took a definite position on the scale of measurement. Consequently, the test did not give an answer, this intellectual person or not, it simply defines his place in the scale of 50 to 150 points.