A scale used to correlate intelligence to the typical changes that occur as a child matures.

French psychologist and educator Alfred Binet theorized that a child who appears to have limited mental abilities is able to perform on a level characteristic of younger children; conversely, a child who appears to be gifted is able to perform on the level of older children. In 1905 Binet, in collaboration with Thèophile Simon, developed a scale on which mental age could be compared to the chronological age. Thus, a bright child's mental age is higher than his or her chronological age.

In 1916, Lewis Terman, a psychologist at Stanford University, devised an intelligence test...