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In a population the inbreeding coefficient � is determined by the relative incidence of the various degrees of consanguineous marriages— uncle–niece or aunt–nephew (C12), first cousin (C22), first cousin once re- moved (C23), second cousin (C33)—which may be related to temporal, geographic, demographic, and economic factors. Using published informa- tion from Spain corresponding to urban and rural areas, in this article we seek to establish how each specific relationship behaves with respect to geo- graphic, demographic, and socioeconomic factors, to determine differential urban–rural patterns, and to study whether the diverse types of consanguine- ous matings relate homogeneously to these factors. For this purpose we per- formed multiple regressions in which the dependent variables were the different degrees of consanguinity previously selected and the independent variables were geographic, demographic, and economic factors. Our results indicate that the various types of consanguineous marriages in Spain are more conditioned by geographic, demographic, and economic variables than by the inbreeding level � (the coefficient of determination was between 0.22 and 0.72; the maximum for � was 0.35). A regional pattern exists in Spain and corresponds to close and to remote kinship, which may be mainly related to economic and family factors. Close relationships appear to be more asso- ciated with economic variables, whereas second-cousin marriages corre- spond largely to rural areas of the Spanish Central Plateau.