Frances L. Ilg, M.D., and Louise Bates Ames, Ph.D., cofounded the Gesell Institute of Child Development (now named the Gesell Institute of Human Development) in 1950 to continue the groundbreaking work of the late Dr. Arnold Gesell. Sidney Baker, M.D., became director of the institute in 1978. Ilg and Ames are the coauthors of several books, including Gesell Institute's Child from One to Six, The Child from Five to Ten, and The Years from Ten to Sixteen.