French psychologist Alfred Binet (1857-1911): in 1899 was appointed to the Commission for the Retarded, a repercussion of a new French law that mandated school for children ages six to fourteen, whose aim was to develop a test to differentiate between normal and abnormal children, so to be able assign each to different classrooms. [14] | French psychologist Theodore Simon (1872-1961): was an intern at the asylum in Perray-Vaucluse, studying abnormal children, during which time he began to work with Binet to develop a test that could measure intellectual development of children ages 3-12. | German psychologist William Stern (1871-1938): reviewed the work of Binet (and others), and developed the idea of expressing intelligence in the form of a single number, the "mental quotient" (1912) as one’s mental age divided by one’s chronological age: [15]
| American psychologist Lewis Terman (1877-1956): refined the Binet-Simon scale (1916) to focus on testing the ‘average’ student and used Stern's proposal that an individual's intelligence level be measured as an IQ: idiot (below 20), imbecile (20-49), moron (50-69), deficient (70-80), dull (80-90), normal (90-110), smart (110-120), superior (120-140), genius (140 and over). [19] | American psychologist Catherine Cox (1890-1984): completed her PhD with a dissertation “On the Early Mental Development of a Group of Eminent Men” (1925) under Terman and expanded this into the 1926 book Early Mental Traits of 300 Geniuses, in which she assigned IQ values to the top 300 geniuses who lived between 1450 and 1850, setting the ceiling genius IQ of 210 to Goethe. [16]. |