Identification. The Foi inhabit the Mubi River Valley and the shores of Lake Kutubu on the fringe of the southern highlands in Papua New Guinea. They divide themselves into three subgroups: the gurubumena, or "Kutubu people"; the awamena, the middle-Mubi Valley dwellers; and the foimena proper, the so-called Lower Foi who reside near the junction of the Mubi and Kikori rivers. The term "Foi" formerly applied to the common language of all three subgroups. It was subsequently employed as an ethnonym by the first missionaries.
Location. Most members of the Foi population inhabit the banks of the middle reaches of the Mubi River, between approximately 143°25′ and 143°35′ E and between 6°27′ and 6°30′ S. The alluvial Mubi River Valley is approximately 670 meters in altitude and abuts the higher ranges of the central highlands in the Southern Highlands Province of Papua New Guinea. The region is in every sense intermediate between the highlands valleys to the north and the coastal regions of the Gulf Province to the south. The southeasterly monsoon brings considerable rainfall during the middle months of the year, while the months between October and March are relatively drier.
Demography. The 1979 Papua New Guinea National Census counted some 4,000 Foi and accounted for another 400 Foi living elsewhere in the country. Foi territory comprises 1,689 square kilometers, and the population density is 2.4 persons per square kilometer. However, the Foi settlement area is restricted to the banks of the Mubi River and the shores of Lake Kutubu; over 60 percent of their land is Reserved for hunting and is not permanently inhabited. The Foi are consequently separated from their neighbors by buffer zones of uninhabited bush. To the north are the Angal-speaking groups of the Nembi Plateau; to the southwest are the Fasu or Namu Po people; to the east are Kewa speakers of the Erave River Valley. Directly south of the Foi are small groups of Kasere, Ikobi, and Namumi speakers of the interior Gulf Province.
Linguistic Affiliation. Foi and Fiwaga are the only Languages within the East Kutubuan Family of the Kutubuan Language Stock. It is closely related only to the languages of the West Kutubuan Family, which includes the Fasu, Kasere, and Namumi languages, but it also exhibits some small amount of cognation with other interior Papuan languages such as Mikaruan (Daribi) and Kaluli.