Developmental psychology focuses on how people mature and learn throughout their lifetime. Developmental psychology involves with a theory in which it divides child growth into different stages which are characterized by qualitative differences in behaviour. There are number of different views about the way in which psychological and physical development proceed throughout the life span. The study of development has been one of the important features of sociology, and deals with causes and consequences of economic change in society. Individuals develop social and emotional skills across the lifespan, with specific consideration to childhood and adolescence is called social development.