Infant & Child Development Stages

The American Academy of Pediatrics divides child development into four major stages. The developmental stages as a whole cover the child from pregnancy to 21 years old. The stages in order of increasing age are infancy, early childhood, middle childhood and adolescence.


Infancy is the first stage of development for children and covers the child during prenatal care and up to 1 year old. The National Network for Childcare lists several developmental milestones that occur during the first year of life 12. The first year is a period of rapid development for motor, language, social, sensory and thinking skills. By the end of the first year, children usually are able to crawl, sit without support, babble and copy simple sounds and actions.

Early Childhood

Early childhood covers years 1 to 4 of a child's life and is also a stage of rapid development. This is an important stage during which children develop basic skills they will use throughout their entire lives. At the end of this developmental period, children should be able to engage in fantasy play, speak fairly clearly in short sentences, and should be able to interact well with other children.

Middle Childhood

Middle childhood spans ages 5 to 10. The major development that takes place during these school-age years are social skills. Children come in contact with not only other children their age, but also adults outside of their family. Self-esteem begins to develop during this stage, and individual personality traits begin to shine. Children also begin to explore more independence during this stage of development.


Adolescence is the final stage of child development recognized by the American Academy of Pediatrics. This stage spans 10 years, the largest of the recognized stages. During this time, children undergo a variety of changes that can be stressful. They not only undergo physical changes associated with puberty, but they also have emotional changes as they begin to further define their decision-making skills and make their own choices. This stage is extremely important and sets the stage for who they will be in adulthood.