Through 37 years as director of the Yale Clinic of Child Development (later renamed Yale Child Study Center), Arnold Gesell pursued the task of observing and recording the changes in child growth and development from infancy through adolescence. Gesell is a maturationist; his descriptions of developmental patterns in childhood emphasize physical and mental growth that he saw as determined primarily by heredity. By carefully observing children in his campus school, Gesell established norms or typical behaviors of children throughout childhood. He categorized these typical behaviors into 10 major areas that he called gradients of growth (Gesell & Ilg, 1949):

  1. Motor characteristics. These include bodily activity, eyes, and hands.
  2. Personal hygiene. These include eating, sleeping, elimination, bathing and dressing, health and somatic complaints, and tensional outlets.
  3. Emotional expression. These include affective attitudes, crying, assertion, and anger.
  4. Fears and dreams.
  5. Self and sex.
  6. Interpersonal relations. These include mother-child, child-child, and groupings in play.
  7. Play and pastimes. These include general interests, reading, music, radio, and cinema.
  8. School life. These include adjustment to school, classroom demeanor, reading, writing, and arithmetic.
  9. Ethical sense. These include blaming and alibiing; response to direction, punishment, praise; response to reason; sense of good and bad; and truth and property.
  10. Philosophic outlook. These include time, space, language and thought, war, death, and deity.

Gesell and his staff created an extensive list of normative information that remains popular with and useful to families and teachers. A parent or teacher concerned about what is normal behavior for a given age can refer to Gesell’s gradients of growth for specific information. In his books, he summarizes the statistical data into statements of what a child is like at a given age.