Marriage. Three rules of marriage are reported: marriage with iai (father's mother's brother's son's daughter), marriage with na (father's sister's daughter), and sister exchange. But, marriages with other categories of women also took place. In marriage ceremonies the asymmetric relationship between wife givers and wife takers were acted out by an unequal exchange of goods (shell valuables, classified as male, and household goods, classified as female). Postmarital residence was patrilocal.
Domestic Unit. Several closely related nuclear families live together in a single dwelling. Each family has its own section and within it husbands and wives have their separate compartments. Cowives and wives of brothers are supposed to form a corporate unit for daily subsistence activities.
Inheritance. Inheritance of land and ritual knowledge follows rules of seniority insofar as the eldest son usually inherits knowledge, and thus power, that his siblings are denied. In rare cases a daughter may become the heir if a man has no son. In former times, the girl was then initiated with the men. Later, her sons inherited the knowledge from her father.
Socialization. Growing up in Iatmul culture is a gradual process of learning and experiencing tasks performed by adults. Children participate actively in the subsistence economy. The acquisition of a new skill and the first performance of a gender-specific task are celebrated for each girl and each boy individually. These ceremonies, naven, were carried out spontaneously by the mother's brother and/or his wife. Children spend much of their time in independent and autonomous groups. Girls grow gradually into women's roles. Boys, on the other hand, have to undergo an initiation which severs them from the women's world and forces them to adopt a male life-style.