The coefficient of relationship is a measure of the degree of consanguinity between two individuals. The term coefficient of relationship was defined by Sewall Wright in 1922, and was derived from his definition of the coefficient of inbreeding of 1921. The measure is most commonly used in genetics and genealogy. A coefficient of inbreeding can be calculated for an individual, and is typically one-half the coefficient of relationship between the parents.
In Islam, a mahram is a family member with whom marriage would be considered permanently unlawful (haram). A woman does not need to wear hijab around her mahram or spouse, and an adult male mahram or husband may escort a woman on a journey, although an escort may not be obligatory.
Sudanese kinship, also referred to as the descriptive system, is a kinship system used to define family. Identified by Lewis Henry Morgan in his 1871 work Systems of Consanguinity and Affinity of the Human Family, the Sudanese system is one of the six major kinship systems.
A cousin is a relative that is the child of a parent's sibling; this is more specifically referred to as a first cousin.
A person's next of kin (NOK) may be that person's spouse, adopted family member or closest living blood relative. Some countries, such as the United States, have a legal definition of "next of kin". In other countries, such as the United Kingdom, "next of kin" may have no legal definition and may not necessarily refer to blood relatives at all.
The immediate family is a defined group of relations, used in rules or laws to determine which members of a person's family are affected by those rules. It normally includes a person's parents, siblings, spouse, and children. It can contain others connected by birth, adoption, marriage, civil partnership, or cohabitation, such as grandparents, grandchildren, aunts, uncles, siblings-in-law, half-siblings, cousins, adopted children, step-parents/step-children, and cohabiting partners. The term close relatives is used similarly.
In law and in cultural anthropology, affinity is the kinship relationship created or that exists between two people as a result of someone's marriage. It is the relationship each party in the marriage has to the family of the other party in the marriage. It does not cover the marital relationship itself. Laws, traditions and customs relating to affinity vary considerably, sometimes ceasing with the death of one of the marriage partners through whom affinity is traced, and sometimes with the divorce of the marriage partners. In addition to kinship by marriage, "affinity" can sometimes also include kinship by adoption or a step relationship.
A sister is a woman or a girl who shares parents or a parent with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a familial relationship, it is sometimes used endearingly to refer to non-familial relationships. A full sister is a first-degree relative.
Family is a group of people related either by consanguinity or affinity. It forms the basis for social order. The purpose of the family is to maintain the well-being of its members and of society. Ideally, families offer predictability, structure, and safety as members mature and learn to participate in the community. Historically, most human societies use family as the primary purpose of attachment, nurturance, and socialization.
Philippine kinship uses the generational system in kinship terminology to define family. It is one of the most simple classificatory systems of kinship. One's genetic relationship or bloodline is often overridden by the desire to show proper respect that is due in the Philippine culture to age and the nature of the relationship, which are considered more important.
In the lineal kinship system used in the English-speaking world, a niece or nephew is a child of an individual's sibling or sibling-in-law. A niece is female and a nephew is male, and they would call their parents' siblings aunt or uncle. The gender-neutral term nibling has been used in place of the common terms, especially in specialist literature.
Laws regarding incest vary considerably between jurisdictions, and depend on the type of sexual activity and the nature of the family relationship of the parties involved, as well as the age and sex of the parties. Besides legal prohibitions, at least some forms of incest are also socially taboo or frowned upon in most cultures around the world.
A sibling-in-law is the spouse of one's sibling, the sibling of one's spouse or the person who is married to the sibling of one's spouse.
Irish kinship is a system of kinship terminology which shows a bifurcate collateral pattern. This system is used by a minority of people living in the Gaeltacht regions of Ireland. Irish kinship terminology varies from English kinship as it focuses on gender and generation, with less emphasis on differentiating lineal vs. collateral.
An uncle is usually defined as a male relative who is a sibling of a parent or married to a sibling of a parent, as well as the parent of the cousins. Uncles who are related by birth are second-degree relatives. The female counterpart of an uncle is an aunt, and the reciprocal relationship is that of a nephew or niece. The word comes from Latin: avunculus, the diminutive of avus (grandfather), and is a family relationship within an extended or immediate family. The gender-neutral term pibling, a shortened form of parent's sibling, may refer to either an aunt or an uncle.
Aboriginal Australian kinship comprises the systems of Aboriginal customary law governing social interaction relating to kinship in traditional Aboriginal cultures. It is an integral part of the culture of every Aboriginal group across Australia, and particularly important with regard to marriages between Aboriginal people.
An avunculate marriage is a marriage with a parent's sibling or with one's sibling's child—i.e., between an uncle or aunt and their niece or nephew. Such a marriage may occur between biological (consanguine) relatives or between persons related by marriage (affinity). In some countries, avunculate marriages are prohibited by law, while in others marriages between such biological relatives are both legal and common, though now far less common.
The Burmese kinship system is a fairly complex system used to define family in the Burmese language. In the Burmese kinship system:
Sesotho – the language of the Basotho ethnic group of South Africa and Lesotho – has a complex system of kinship terms which may be classified to fall under the Iroquois kinship pattern. The complex terminology rules are necessitated in part by the traditional promotion of certain forms of cousin marriage among the Bantu peoples of sub-Saharan Africa. Most of the terms used have common reconstructed Proto-Bantu roots.
Collateral is a term used in kinship to describe kin, or lines of kin, that are not in a direct line of descent from an individual. Examples of collateral relatives include siblings of parents or grandparents and their descendants. Collateral descent is contrasted with lineal descent: those related directly by a line of descent such as the children, grandchildren, great-grandchildren, etc. of an individual. Though both forms are consanguineal, collaterals are neither ancestors nor descendants of a given person. In legal terminology, 'Collateral descendant' refers to relatives descended from a sibling of an ancestor, and thus a niece, nephew, or cousin.
