Kinship is the most basic principle of organizing individuals into social groups, roles, and categories. It was originally thought to be determined by biological descent, a view that was challenegd by Schneider (1984). The crux of his argument was that anthropologists had founded the domain of “kinship” on the notions of human reproduction and the biologically defined relatedness of their own Euro-American culture. Human reproduction and notions of biological relatedness cannot be presumed to elsewhere structure people’s social relationships.
The word kinship can refer more broadly to any emotional relationship. This can also refer to ideas which are mathematically related.
In its most general sense, kinship can be used in reference to similarity; for instance, a car is akin to a truck. In some cultures, the formal establishment of kinship involves various customs and obligations.
Anthropologists have studied different systems of kinship in a wide variety of cultures; see family.