Marriage. Members of the same matriclan are not supposed to marry. Cross-cousin marriage is preferred, especially between a woman and her father's sister's son. Residence after marriage is uxorilocal. Polygyny is allowed but is not common. Many marriages simply lapse through desertion. Divorce according to Islamic law is possible.
Domestic Unit. The core of the traditional domestic unit consists of a woman, her married and unmarried daughters, and her daughters' children. Her adult sons or grandsons who are not yet married sleep in the local prayer house ( surau ); those who are married sleep as guests in the houses of their wives. Her husband is a guest in her house, as are her daughters' husbands. Each married woman has her own room in which to receive her husband. Members and guests of the household socialize and work in a great common room that runs full length through the middle of the traditional house, with rows of bedrooms on either side. As the original family matures and expands, older women without young children move to small houses built near the great house. Such house compounds are heritable property occupied by succeeding generations of women and their families.
Such traditional houses still exist in most nagari, but now they are often outnumbered by smaller and more modern houses occupied by nuclear or stem families in which men are less clearly guests in the houses of their wives. If a man builds a modern house for his wife using his own resources, the house is his until his wife or daughter inherits it. Households in rantau areas also tend to be nuclear or stem families.
Inheritance. There are two types of property in traditional law ( adaik ): harato pancarian (earned property) and harato pusako (ancestral property). Earned property generally involves goods produced for exchange: the means of production are individually owned, and can be inherited by children of either sex. Rules of distribution of such inheritance may be Islamic, in which case male heirs receive full shares and female heirs half shares. Or, traditional rules may be followed, in which case the heirs of males are males and the heirs of females females. Examples of harato include craft goods and newly acquired land.
Ancestral property involves goods produced for immediate consumption and the means of production, which are communally owned and can be inherited only by females. The best example of harato pusako is land for wet-rice production. A right to the use of such land passes from mother to daughters and is closely supervised by the matrilineal group that owns it. Usually this is at the sabuah paruik (sublineage) level, but it might be at higher or lower levels depending on the segmentary structure of the actual kinship group and the number of generations since the acquisition of the land. Also, if there are many heirs and the plot of land is not large, the right to use the land may be rotated year-by-year among the different heirs. The male leaders (mamak, or "mother's brother") of the matrilineal group are the arbiters in matters of inheritance.
Minangkabau distinguish between harato pusako tinggi or "high ancestral property" and harato pusako randah or "low ancestral property." High ancestral property has been inherited over a period of so many generations that the incident of its initial acquisition has been forgotten, whereas low ancestral property has been inherited for only a few generations, and the incident of its initial acquisition through labor or purchase is still remembered. Low ancestral property is available for use only by the heirs of the ancestress who first acquired it. High ancestral property is available for use by a wider range of members of the corporate landholding group.
The relative importance of these two modes of inheritance, one for earned property and the other for ancestral property, varies from place to place in the Minangkabau area. Nagari in the well-watered plains, in which wet-rice production is the main economic concern, are more involved with ancestral property (harato pusako) and matrilineal law (adaik parapatiah). Those located in the dry hills and in urban areas, where the production of commodities is more important than the production of rice, are more involved with earned property (harato pancarian) and patrilineal law (adat temenggong). Also, patrilineal inheritance is more important among royal and aristocratic families and in communities where fundamentalist Islamic precepts are important.
Socialization. Mothers and fathers socialize children. Weaning may be traumatic, but toilet training is not early or harsh. A father helps his children gain an education and he takes a strong interest in helping find appropriate husbands for his daughters. Children also receive the attention of the mother's brother, who as an adult male of the same corporate group has a strong interest in their success. Older siblings are strongly involved in the socialization of their younger siblings.