Marriage. In the traditional marriage system, matriLineages were often paired and both matrilateral and patrilateral cross-cousin marriage were strongly favored. Marriages to members of the same matrilineage were forbidden and have not occurred. In the past, polygyny was not uncommon and leaders occasionally had several wives. It is rare in Contemporary Siwai. Divorce was common and widows and widowers normally remarried. Although cross-cousin marriages within villages remain common, many marriages are now contracted between Siwais and members of other linguistic groups from other parts of the country or even beyond. Postmarital Residence was initially virilocal, but later it often shifted to avunculocal or uxorilocal.
Domestic Unit. Most households are nuclear families; extended households are very rare. Youths often sleep in separate houses from their parents.
Inheritance. Personal effects are usually inherited by the oldest son. Until very recently such goods have been few and inconsequential.
Socialization. Children are normally treated with affectionate indulgence by their parents and disciplining is often ineffective. Punishment and rewards are normally verbal. Conflicts between children, especially brothers, are more common than disputes and conflicts with parents, who are accorded considerable respect. Primary school education is now effectively universal and many children go on to Secondary and tertiary education.