Arnold Gesell, famed child psychologist, was born in Wisconsin. He earned his bachelor's degree from the University of Wisconsin. He gained his Ph.D. from Clark University in 1906 where he specialized in child development by studying with G. Stanley Hall. Later, in 1915, Gesell received his M.D. from Yale. He was selected as an assistant professor at Yale, where he created the Clinic of Child Development and served as director from 1911 to 1948.
Gesell was one of the first to fully institute a quantitative study of human development for youths focusing on studying a specific small number of children. He began with pre-school, then 5-10 year olds, and then 10-16 year olds. Gesell concluded that mental and physical developments in youths are analogous processes. His research and reports had a widespread affect on both parents and educators. These were used to create the Gesell Development Schedules. Areas emphasized on these tests include language and motor development, adaptive behavior, and personal-social behavior. The results of the test are expressed as a developmental quotient (DQ), representing "the portion of normal development that is present at any age."