closekin

Closekin is a term used in genetics, anthropology, and sociology to describe individuals who share a high degree of relatedness due to recent common ancestry or strong social ties. In biological contexts, close kin typically refers to relationships within the first or second degree of kinship, such as parent–child, full siblings, grandparent–grandchild, half-siblings, and avuncular ties. These relationships are often characterized by kinship coefficients, with close kin corresponding to coefficients around 0.25 or higher.

In anthropology and kinship studies, close kin networks influence patterns of inheritance, marriage rules, residence, and collective decision making. In many cultures, obligations and access to resources are organized along close-kin lines, shaping social organization and resilience.

In sociology and economics, research on close kin examines how tight kin networks provide social capital, caregiving, financial support, and risk sharing. The concept also informs studies of mating systems, population structure, and social support systems.

Measurement and ethics: Modern methods combine pedigree information with genomic data to estimate kinship, while safeguards protect privacy and consent given the sensitivity of familial relationships. Etymology: from "close" and "kin," highlighting proximity in ancestry or social ties.