Social Organization. Keraki society is divided into tribes, with each tribe having three or four local section groups. Most villages belong predominantly to one section or another. Even when two sections are represented in the same village, section members live together. These local section groups, united by ties of kinship, common interest, and fellowship, are the most important units of Keraki social Organization. They hunt together, make sago together, and often garden together. They cooperate in ritual matters: the group owns the major bullroarer and combines to initiate boys, it cooperates in fertility and death rituals, it acts as a group in the exchange of marriage partners, and it collectively organizes feasts. Formerly it raided together. These exogamous local groups become affinally linked to one another through exchange marriages. The two husbands become tambera or exchange partners, and they perform ritual services for each other's children. Other males of approximately the same age become kamat (sisters' husbands or wives' brothers), offering hospitality and friendship to their counterparts in the opposite local group.
Political Organization. The Keraki recognize hereditary headmen of the local groups described above. However, since these local groups are patrilineally organized and typically very small, consisting of only about thirty persons, the headman is usually the eldest active male. Leadership passes to a younger brother and then to the eldest son of the original headman. The headman exercises very little real authority. His "decisions" merely reflect the general consensus of opinion. There is no formal leadership above the local group level.
Social Control. Social control within the group is maintained largely through a sense of conformity, knowledge of the importance of reciprocity, feelings of in-group solidarity and support, and general conservatism. These are bolstered by fears of public reprobation or ridicule, retaliation through violence or sorcery, and the possibility of supernatural retribution.
Conflict. Conflict within the local group is rare, owing to the social control mechanisms described above. Occasional thefts and sexual jealousies are the most common exceptions. Fighting with Keraki people from outside the local group is called guwari, in which the men from one village descend in open invasion on the men from another village. Loud, wordy quarrels might develop into general brawls, sometimes with sticks and arrows used as weapons, but these fights usually end in reconciliation. In contrast to this was the moku, or head-hunting raid, directed against non-Keraki people, most commonly the Gunduman. These raids took the form of unexpected, often predawn raids. Heads were quickly severed with bamboo knives and attached to cane head carriers, whereupon the entire party fled. Once in their camp, the raiders cooked the heads, often eating a bit of flesh, usually from the cheek, and cleaned the skulls, which they erected on poles as trophies. Men who had taken heads achieved status and some measure of influence within the group. The Keraki were comparatively peaceful, however, more often being the victims of the aggressive Marind or Wiram people than the victors themselves, and their head-hunting raids were rather infrequent.