Kinship. The key unit among rural Aveyronnais farmers is the ostai or "house," a farm unit associated with an ongoing patriline (designated by a family name) and a fixed location in space (designated by a place name). Kinship is figured bilaterally, but the core of the ostai is an unbroken, singlestranded father-to-son line. In general, the eldest son carries on the line, inheriting the farm and fathering its next heir. Other children are distanced from the line. They may move away from the farm, keeping the family name but losing identity with its named place. Alternatively, they may stay but must remain unmarried, becoming collaterals rather than ascendants to the line. In this system, more emphasis is placed on descent than on affinal ties. The key relationship is Between father and eldest son. The mother-eldest son tie is also important: an in-marrying woman, permanently alien to the line, establishes herself within it as mother to its heir, her eldest son, a relationship she is expected to carefully develop and defend in turn against the demands of his own wife, her daughter-in-law.
Marriage. An ostai heir is expected to marry the daughter of an ostai of equal status to his. The bride, bringing a dowry of cash or movable goods, joins the ostai household of her husband and his parents. In the absence of a male heir an heiress is designated; she is normally expected to marry a younger son from a socially superior ostai, who also brings a dowry and moves into the household of his wife and parents. Otherwise, daughters and younger sons are expected to marry someone of roughly equivalent social status, do not receive dowries, and set up households separate from the parents of either. Divorce is not tolerated and premature widowhood of an in-marrying spouse is problematic. If childless, she or he may be sent away with her or his dowry. A widowed inmarrying spouse with small children is expected to marry the brother- or sister-in-law who will replace the deceased as heir to the ostai. If the children are nearly grown, the widow or widower may temporarily take over the ostai until the legitimate heir is able to do so.
Domestic Unit. The ostai household ideally takes a stem family form: an older couple, their eldest son and heir with his wife and children, and their unmarried daughters and younger sons. This pattern, requiring some measure of prosperity, has become more frequent, at least in some areas of the Aveyron, as the local economy has moved away from meager subsistence levels. Nonostal households generally take a nuclear family form.
Inheritance. The Aveyron, in a region of southwestern and central France where impartible inheritance was practiced historically, stands out today as a department in which this practice persists most strongly, despite its illegality since the promulgation of the Napoleonic Code nearly two centuries ago. Generally, farms are passed intact from father to eldest son. Farm value is routinely underassessed, and the share legally due to daughters and younger sons frequently remains an unpaid and unexpected promise. Recourse through the court system is generally considered an unattractive alternative to the social pressures and internalized values underpinning the "rights of the eldest" ( droit de l'ainesse ). The incidence of male primogeniture inheritance, like that of stem family households, has increased with growing prosperity.