The Chittagon Hill Tracts, the only mountain area of East Pakistan, were at first settled by the hill men, Mongoloid people, with the shifting cultivation. The immigration of the plains men, Bengali people, has brought the paddy cultivation, and the conflicts and acculturation between both peoples.
The writer studied the population geography of this area at the field survey in 1964 with following results.
1) The population density is higher than 70per square mile in the settlements of Chakma, Marma and Tippera tribes with the paddy cultivation, occupying broader valley floors in northern and central parts, and is less than 70per square mile in the settlements of Marma tribe with the paddy cultivation on mountain lands.
2) Hill men consists of many tribes, whose places of origin and degree of acculturation are various. But they are equally enthusiastic to take the Bengali culture.
3) The population of Bengali people shows male surplus, the high percentage of Islamism, and the inclination to the urban and the secondary and tertiary industries. The tribes are exclusively Buddists and are living on the agriculture, and their sex ratio is normal.
4) The natural growth of population is generally high. The social growth is caused by the Bengali immigration to the westernmost region and the movement of hill men from the Kaptai reservoir area.