At the turn of 20th century, the intellectual disability field was strongly influenced by European thinking. Specially the intellectual disability field was influenced by an English doctor, Tredgold, A.F. who defined intellectual disability as social incompetency/amentia by mental defects. Under the influence of a French psychologist, Binet A., Goddard, H. H. who found Binet’s intelligence test, intelligence tests were spread by Terman, L.M., Kuhlmann, F.. and Terman, L.. And Goddard made contribute to make the legend that persons with mental deficiency were the source of social evils.At about in 1920s, IQ and intellectual tests, however, received many harsh criticism. Bagly,W.C., for example, criticized that IQ’s constancy was against democracy and universal education, proposing that any person could achieve horizontal development even if the person couldn’t have any vertical development. Godddard and Terman regretfully reformed their position without totally acceptingcriticism.In 1929, US was attacked by the Great Depression. The White House Conference on Child health and Protection was convened by the president Hoover, H.C., to meet the crisis of dependent children. The Conference readjusted the term of mental deficiency to avoid the confusion then prevailing because feeble-minded was used as a generic term for all grades of deficiency and also as a specific term for highest grade. The White House Conference also proposed that the generic term “mental deficiency” would be divided into two groups. One is of feeble-mindedness which has social incompetency and the other is of subnormality. It became the fountainhead for a two-group approach, differentiating those below-average children of low intelligence from those who don’t show social competency. The White House Conference, also, proposed many ways of social control of the mentally deficient.From early time Doll, E.A. expressed critical remarks against intelligence tests which were used as a tool of diagnosis of mental deficiency, asserting that mental deficiency or feeble-mindedness should be judged clinically, with the help of the history of development, education and a home environment. After the White House Conference, Doll developed the Social Maturity Scale which would aim to measure the growth of social behaviors. Doll envisioned the measurement tool would take over the position of intelligence tests. In 1941, Doll proposed the inclusive concepts of mental deficiency-social incompetence, deficiency or defects of development, constitutional origin, duration to adulthood, incurable(although amenable) .