The Sambia is a small, agrarian, partially nomadic tribe that lives in the Highlands of New Guinea. Their villages are organised patrilineally and any two villages are either bonded by marriage or perpetually at war.
The most interesting aspect of The Sambia are their sexual beliefs, in particular their male rites of passage. They believe that both sexes are born with an organ called a tingu that releases the female's menstural blood and male's semen. All females' tingus are born full of blood and in full working order, however males must develop the ability to produce semen through certain practices throughout childhood.
Between the ages of 7 and 10, male children are taken to a men's house in the village for spiritual education and training. Until 10, the key aspect of this practice is the fellatio of older boys. When a boy ingests semen it goes into his tingu and therefore is a valuable gift. Tribe members explain that the semen is a more powerful version of breast milk. As boys mature they seek out fellatio partners and begin to receive arousal from giving fellatio; eventually it is their turn to receive.
Masturbation, wet dreams, and contact with a female's sexual fluids are considered very dangerous at early stages of development. Only once their education is complete (age 17 to 21) can they marry and engage in the dangerous practice of heterosexual intercourse; at this time they must cease all homosexual encounters (newlyweds occasionally engage in fellatio).
Both homosexual and heterosexual incest are considered taboo. Only 5% of tribe members stray from the entire routine in any way.
Distilled from: the online notes for the Introduction to Cultural Anthropology class at the State University of New Jersey <http://icarus.ubetc.buffalo.edu/users/apy106/cultures/sambia.html>