Population growth is linked to over all levels of economic development and every society follows a typical pattern of development related to population growth.

If the society is under developed or technological backward the pace of population growth will be slow and low because per capita earning capacity of such unskilled society will remain minimum. People from search society will be engaged in manual work, they will be suffering from malnutrition, so the death rate will be higher as compared to people from society of educated and skilled people.

In developed society death and birth rate being low the difference between them is very small so the growth rate is always low.

The stage between backwardness and skilled people is called transitional stage in which growth rate of population is very high whereas death rates are brought down through various methods.

Society behaviour takes time to adjust with new situation of relative prosperity and longer life span, so population explosion takes place during transition period.

There are basically three stages of population growth

Primitive stage (Under developed Society) - In this stage society is underdeveloped and technological backward the population growth rate is low and death rate is very high due to lack of health and medical facilities; Therefore, the population growth is low.

Stage 2 (developing countries) - In developing countries the birth rate and death rate are very high so the net growth of population remains low. Birth rates are high because people are illiterate and ignorant and death rate is high due to lack of medical and health facilities.

Stage 3 (developed countries) - Here the birth rate is low as well as the death rate is low, so the population growth is also low. Birth rate is low because people are educated, and death rate is low because of availability of health and medical facilities.

Transitional stage - It is the stage between backward and advanced society. In this stage growth rate of population is very high whereas death rates are brought down due to better medical facilities and other advancement therefore this period or stage is associated with a population explosion.