Phases of development are as follows:

1. Infancy (0-3 years): Its characteristics are:- 

1. Very fast development of size, shape, weight, height alongwith mental, social and emotional behaviour. 

2. The child is fully dependent on others. 

3. The child is very selfish and shows unsocial behaviour. 

4. The child wants everything for himself/herself without considering needs of others.

2. Childhood (6 to 12 years): Its characteristics are: 

1. The child grows and develops at slow rate. 

2. The child starts feeling pleasure in handling his/her own needs. 

3. The child starts socialising by sharing his/her toys with others. 

4. The child starts expressing his/her emotions to the society and learns to balance and control his/her emotions.

3. Adolescence (12 to 20 years): Its characteristics are:- 

1. The adolescent undergoes physical changes such as breast development and menstruation in girls and physical structure, looks and the general appearance in boys. 

2. The adolescents live in their hypothetical world. Aim at something beyond their access and disappointed on failure.

3. At this stage boys are more prone to sexuality than the girls. Boys and girls become the blind followers of love. 

4. They are overpowered by emotions and want to do something adventrous.

4. Adulthood (21 to 40 years): Its characteristics are:- 

1. At this stage, person accepts the responsibility. 

2. They make their own decisions. 

3. Inner conflicts are reduced.