Comparative anthropological studies of kinship and marriage reveal the artificial character of such concepts. What most people conceive to be a 'natural' order of kinship differs in multiple ways in different socio-cultural contexts, since the domain of kinship and marriage is applied to classify societal wholes. The presentation will illustrate this classificatory quality by examples taken from (1.)the Book of Genesis, since this model is also applied (among others) in many contemporary Muslim societes, and (2.) from the Adivasi community of the Gadaba, about 100 000 people in the Orissan district of Koraput of Middle India.