Genealogical method

The genealogical method is a well-established procedure in ethnography. It was initiated by early ethnographers to identify all-important links of kinship determined by marriage and descent. Genealogy or kinship commonly plays a crucial role in the structure of non-industrial societies, determining both social relations and group relationship to the past. Marriage, for example, is frequently pivotal in determining military alliances between villages, clans or ethnic groups.

In the field of epistemology the term has come to be used, by extension, to characterize the philosophical method employed by such writers as Friedrich Nietzsche and Michel Foucault.

...
Wikipedia