Current Wentzville, Missouri Population, Demographics and stats in 2016, 2017.
David Wechsler. developed an intelligence test for adults in the US (WAIS), an intelligence test for children (WISC, which has been revised and is now the WISC-IV), and an intelligence test for preschool (WPPSI).
Mental age was first defined by the French psychologist Alfred Binet, who introduced the intelligence test in 1905, with the assistance of Theodore Simon. Binet's experiments on French schoolchildren laid the framework for future experiments into the mind throughout the Twentieth Century.