Bougainville displays great cultural diversity in a relatively small region. Although the cultures share some commonalities, there is a range of traditional beliefs, customs and languages.
While the classification of languages and dialects can vary, according to Regan & Griffin (2005) there are at least 19 spoken languages indigenous to Bougainville and many more dialects.
Tok Pisin (sometimes referred to as Neo-Melanesian, Melanesian Pidgin or Pidgin English) is the language most widely spoken in Bougainville and the lingua franca of the region.
Family inheritance is generally, although not exclusively, matrilineal. Bougainvilleans are overwhelmingly Christian although traditional beliefs linked to a rich spirituality remain, particularly relating to the spirits of ancestors and the deceased.
 (Regan & Griffin, 2005, p. xxvii)
 (Regan & Griffin, 2005, p. 31)