There is a wide variation in forms of descent and kin group among the Swahili settlements. Country-towns are divided into moieties, and these into wards or quarters. The wards, composed of clusters of cognatically related kin, are the corporate and landholding units. Marriage is preferred between cross and parallel cousins; it is seen largely as a way to retain rights over land within the small kin group. Authority is held by senior men and women, and all local groups are regarded as equal in rank.
Within the Stone-towns, the main social groups are in most cases patrilineal subclans and lineages. The clans are distributed among the coastal towns and even in southern Arabia, from which immigrant origin is often claimed. These towns are likewise divided into moieties and constituent wards, the former once providing indigenous forms of government; their structural opposition is expressed in fighting at certain rituals, football matches, and poetry competitions. The corporate groups are the lineages, segments of subclans, that, in the past, acted as business houses and owned the large permanent houses that are so marked a feature of these towns. The subclans are ranked, position depending largely on antiquity of claimed immigration and settlement, as well as on commercial wealth and standing. Members of these mercantile lineages are known as "patricians."
Marriages are centrally important and weddings the most elaborate rituals. In the Stone-towns, the preferred marriage forms vary. For firstborn daughters, they should be between close paternal parallel cousins. Bride-wealth and dowry are both transferred, as are residential rights (not full ownership, which is vested in the lineage) for the daughter in her lineage house, marriage thus being uxorilocal. Marriages of later-born daughters are more usually with cross cousins, often in neighboring Stone-towns so as to make and retain useful commercial ties. Stone-town weddings are traditionally elaborate and costly, the bride needing to show her virginity and so her purity, which reflects upon the honor and reputation of her husband. Country-town weddings are basically similar but less elaborate and less ritualized.
Divorce is permitted under Islamic law: it is easy for husbands but extremely difficult for wives. The marriages of firstborn patrician daughters are monogamous (although concubinage was frequent), and divorce has been rare; all other marriages have often been polygynous, and divorce has been and is extremely common, as high as 90 percent in some areas.
Today Swahili women undergo initiation (without physical operation) at puberty, in order to be permitted to marry. Boys nowadays are not initiated but are circumcised in infancy; in the past there was more elaborate male initiation. Both boys' and girls' socialization after infancy takes the form of Islamic education in the Quranic schools attached to mosques, and consists largely of moral and theological learning based on knowledge of the Quran, although instruction in poetry and music has been an important part of their training to become pious Muslims. Today most children also attend nonreligious schools in order to acquire "Western" education, but religious education retains its central place, and overtly Christian schools are totally avoided.