Dr Arnold Lucius Gesell (1880-1961) was a pioneer in the field of child development. His set of normal milestones for children is still widely used by pediatricians, psychologists and other professionals who work with children.

Gesell was born in Alma, Wisconsin. He studied psychology at Clark University, receiving his PhD in 1906, continued in medicine at Yale, where he gained his MD in 1915. At Yale, he started fairly soon with a clinic of child development, and between 1915 and 1948 he was professor of child hygiene at Yale.

He worked on feral children and adoption, but his main interest was the normal development of children. To this end he constructed the Gesell dome , a one-way mirror shaped as a dome, under which children could be observed without being disturbed. Measurements done in these sessions (which were annotated and filmed extensively) contributed to a set of milestones which are still being used by child health professionals.

External links

• Gesell's archives
• Historical link collection (with photo)