Consanguinity and social change: an isonymic study of a French Peasant Population, 1870–1979

Abstract

SummaryThe evolution of the inbreeding coefficient estimated by the isonymic method is studied in a rural canton of mid-France, using data divided into 10-year intervals of 6277 marriages recorded in the civil registers between 1870 and 1979. The results show a strong diminution of the values of F from 1930 onwards, probably related to the drop in population due to exodus from rural areas. The evolution of the inbreeding coefficient observed in three large occupational groups (farmers, craftsmen and labourers) shows that after 1930 it was only the farmers who maintained the low positive values of F. The coefficient of genetic relationships by isonymy (Ri) calculated among the principal occupational groups shows their community of origin, which is still perceptible today.