Four distinct periods of growth, development, and learning that build on each other as children and youth progress through them.

Each planes last for about 6 years, ending when the individual reaches maturity at approximately 24 years of age.

 

Infancy	0 - 6	the period of the "absorbent mind” and sensitive periods
Childhood	6 - 12	the period of reasoning and abstraction
Adolescence	12 - 18	construction the "social self,” development of moral values and becoming emotionally independence
Maturity	18 - 24	understanding of the self and the search to know one's place in the world