Human stages of growth and development are differentiated by age and key stages of scientifically supported psychomotor development. Psychomotor development is progress in mental and motor skill activity. The process of growing and developing begins on the cellular level even before conception in the womb and continues throughout life until death. The scientific community divides human growth into stages according to age and assesses psychomotor development as a human develops motor skills and reaches cognitive milestones. Most human stages of growth and development occur in infancy, childhood and adolescence.
