The outstanding progress of the second edition of Stanford-Binet Intelligence Scale is to introduce the concept of IQ and apply it to the whole world.
IQ indicates the relative level of intelligence and becomes an index to compare children's intelligence.
Professor Tuimeng of Stanford University published the Stanford-Binet Intelligence Scale in 19 16, which introduced the concept of specific IQ for the first time and began to use IQ as an indicator of individual intelligence level.
The basic assumption of ratio IQ is that intellectual development is in direct proportion to age growth, which is a linear relationship. However, with the growth of people's age, IQ stops growing, and enters a platform period around the age of 26, so IQ is not suitable for old age.