Contrary to conventional anthropological understanding, descent groups need not always be wealth- or office-transmitting groups, but can be principally feast-sponsoring groups. Sursurunga matrilineages are activated by individual's combined participation in feasting events, but individual's reasons for participating in feasts vary and often have little to do with matrilineal group membership.This study of Sursurunga mortuary feasting shows that the analysis of groups-in this case, matrilineal descent groups-is best conducted by attention to the reasons that the individuals who comprise those groups act as they do. The salience of group membership cannot be seen as simply the blueprint for social life, but also as the outcome of social life.