Social structure and consanguinity in a French moutain population (1550-1849)

International audienceSociocultural factors play a crucial role in the variation of consanguinityin a population. The choice of specific matrimonial strategies canfavor the closure or opening of the group to the outside, whereas differentialfertility affects the gene flow from one generation to another. In the presentstudy we analyzed the role of socioprofessional groups in the maintenanceof endogamy and consanguinity in a French Alpine valley: Vallouise in theBrianc¸on area. In mountain environments, where the reproductive space islimited and quickly saturated, the autochthonous families adopt diversifiedmatrimonial strategies. These marriage practices tend to prevent fragmentationof agricultural property. We analyzed the matrimonial behavior in thetwo main social groups of this population (de´cideurs and farmers) from 1550to 1849. To better understand the behavior of the two social groups, weconsidered the two components of consanguinity, close and distant. Ourstudy showed that the two groups had similar behavior regarding consanguinity.The way to prevent fragmentation of the patrimony was to choosea consanguineous spouse. This type of strategy inevitably leads to a highpercentage of endogamy, which in this region of the Alps exceeded 90%through many centuries