The indigenous population of Papua New Guinea is one of the most heterogeneous in the world. Papua New Guinea has several thousand separate communities, most with only a few hundred people. Divided by language, customs, and tradition, some of these communities have engaged in tribal warfare with their neighbors for centuries.

The isolation created by the mountainous terrain is so great that some groups, until recently, were unaware of the existence of neighboring groups only a few kilometers away. The diversity, reflected in a folk saying, “For each village, a different culture,” is perhaps best shown in the local languages. Spoken mainly on the island of New Guinea–composed of Papua New Guinea and the Indonesian province of West Papua–about 650 of these languages have been identified; of these, only 350-450 are related. The remainder seem to be totally unrelated either to each other or to the other major groupings. Native languages are spoken by a few hundred to a few thousand, although Enga, used in Enga Province, is spoken by some 130,000 people. Most native languages are extremely complex grammatically.

Melanesian Pidgin serves as the lingua franca. English is spoken by educated people and in Milne Bay Province.

The overall population density is low, although pockets of overpopulation exist. Papua New Guinea’s Western Province averages one person per square kilometer (3 per sq. mi.). The Chimbu Province in the New Guinea highlands averages 20 persons per square kilometer (60 per sq. mi.) and has areas containing up to 200 people farming a square kilometer of land. The highlands have 40% of the population.