Psychologist and pediatrician Arnold Gesell was born in 1880.

Arnold Gesell was a pioneer in the field of child development and one of America’s leading authorities on child-rearing in the 1940s and 1950s. His research and books greatly influenced parents and educators during this period. Gesell began his revolutionary studies of child development while a graduate student at Yale University in the early 1900s, where he founded the Clinic of Child Development. His use of an early video camera to observe and record normal infants and children added greatly to the data collected on the subject. He was one of the first clinicians to quantify data for more objective study, and he developed one of the first intelligence tests for infants. He identified behavioral norms for infants and children at certain stages of development, which continue to be used today. In 1950, the Gesell Institute of Human Development was founded in his honor.

Science NetLinks
Growth Stages 1: Infancy and Early Childhood (3–5) introduces students to the stages of human growth and development that take place during infancy and early childhood.

Growth Stages 2: Middle Childhood and Early Adolescence (3–5) introduces students to the stages of human growth and development that take place during middle childhood and puberty.

In the Science Update Adolescent Slowdown (6–12), a researcher describes recent findings that suggest the brains of adolescents are actually slowing down in their ability to process emotional information.

The Science Update Sticky Mittens (6–12) focuses on a recent study that attempted to separate the mental development of babies from their physical development by giving three-month-olds Velcro mittens with which they could pick up objects.

Nature and Nurture (3–5) helps students develop an understanding of the roles both nature and nurture play in determining an individual’s traits.

Illuminations
Understanding a Child’s Development of Number Sense (K–2) features three video clips that illustrate the possible range in students’ understanding of numbers and number relationships between kindergarten and second grade.