This article analyzes the link between formal friendship and a matrimonial system among the Apinaje people. Starting with an analysis of formal friendship among the Jê, it presents existing similarities and differences among various peoples in the same linguistic family. Then, after describing the Apinaje's formal friendship formed by Nimuendajú and DaMatta, a formal friendship transmission model among the Apinaje is proposed. Finally, the paper shows that formal friendship recreates a virtual system of moieties, and based on ethnographic data argues that formal friendship is used for creating affinity in social relationships, overlapping, in some cases, consanguinity.
Formal Friendship; Apinaje; South American ethnology; Jê people