The major stages of human development are:

(i) Prenatal period (from conception to birth): In this period, the single-celled organism changes into a human baby within the womb.

(ii) Infancy and toddlerhood (birth-2 years): Rapid changes in the body and brain help several sensory, motor, social and cognitive capacities to emerge.

(iii) Early childhood (2-6 years): Motor skills are refined, language develops, ties are formed with peers, and the child learns through play.

(iv) Middle childhood (6-11 years): These are the school years when the child acquires literacy skills, thought processes are refined, friendships emerge and self-concept is formed.

(v) Adolescence (11-20 years): This period is marked by puberty which signals the onset of rapid physical and hormonal changes, emergence of abstract thinking, sexual maturity, stronger peer ties, sense of self and autonomy from parental

Control.

(vi) Early adulthood (20-40 years): This is the stage of life when the youngster leaves home for the sake of education, or to find a career, and to form intimate relationships leading to marriage and having children.

(vii) Middle adulthood (40-60 years): At this stage the person is at the peak of his/her career. There is a need to help children begin independent lives, and to look after own parents who are ageing.

(viii) Late adulthood (60 years till death): This period is marked by retirement from work, decrease in stamina and physical health, bonding with grand-children, and dealing with impending old age and death of self and spouse.