Caption:

Gesell test objects including a bell, two rattles, a cup, ten large and six small wooden blocks. These items were used by the American developmental psychologist and physician Dr Arnold Gesell (1880-1961) in his Clinic of Child Development at Yale University, Connecticut, United States. Gesell studied hundreds of children to chart the normal stages of child development. in the 1920s, Gesell had a special observation dome built so that infants could be filmed doing simple tests, such as making towers of bricks. Gesell's work formed the basis of routine testing of children by healthcare workers. It was also used to match up children with adoptive parents.