Kinship is the most universal and basic of all human relationships and is based on ties of blood, marriage, or adoption.
There are two basic kinds of kinship ties:
- Those based on blood that trace descent
- Those based on marriage, adoption, or other connections
Some sociologists and anthropologists have argued that kinship goes beyond familial ties, and even involves social bonds.
Kinship is a "system of social organization based on real or putative family ties," according to Encyclopaedia Britannica. But in sociology, kinship involves more than family ties, according to the Sociology Group:
"Kinship is one of the most important organizing components of society… This social institution ties individuals and groups together and establishes a relationship among them."
Kinship can involve a relationship between two people unrelated by lineage or marriage, according to David Murray Schneider, who was a professor of anthropology at the University of Chicago who was well known in academic circles for his studies of kinship.
In an article titled "What Is Kinship All About?" published posthumously in 2004 in "Kinship and Family: An Anthropological Reader," Schneider said that kinship refers to:
"the degree of sharing likelihood among individuals from different communities. For instance, if two people have many similarities between them then both of them do have a bond of kinship."
At its most basic, kinship refers to "the bond (of) marriage and reproduction," says the Sociology Group, but kinship can also involve any number of groups or individuals based on their social relationships.
Sociologists and anthropologists debate as what to types of kinship exist. Most social scientists agree that kinship is based on two broad areas: birth and marriage; others say a third category of kinship involves social ties. These three types of kinship are:
- Consanguineal: This kinship is based on blood-or birth: the relationship between parents and children as well as siblings, says the Sociology Group. This is the most basic and universal type of kinship. Also known as a primary kinship, it involves people who are directly related.
- Affinal: This kinship is based on marriage. The relationship between husband and wife is also considered a basic form of kinship.
- Social: Schneider argued that not all kinship derives from blood (consanguineal) or marriage (affinal). There are also social kinships, where individuals not connected by birth or marriage may still have a bond of kinship, he said. By this definition, two people who live in different communities may share a bond of kinship through a religious affiliation or a social group, such as the Kiwanis or Rotary service club, or within a rural or tribal society marked by close ties among its members. A major difference between consanguineal or affinal and social kinship is that the latter involves "the ability to terminate absolutely the relationship" without any legal recourse, Schneider stated in his 1984 book, "A Critique of the Study of Kinship."
Kinship is important to a person and a community's well-being. Because different societies define kinship differently, they also set the rules governing kinship, which are sometimes legally defined and sometimes implied. At its most basic levels, according to the Sociology Group, kinship refers to:
Descent: the socially existing recognized biological relationships between people in the society. Every society looks at the fact that all offspring and children descend from their parents and that biological relationships exist between parents and children. Descent is used to trace an individual's ancestry.
Lineage: the line from which descent is traced. This also called ancestry.
Based on descent and lineage, kinship determines family-line relationships-and even sets rules on who can marry and with whom, says Puja Mondal in "Kinship: Brief Essay on Kinship." Mondal adds that kinship sets guidelines for interactions between people and defines the proper, acceptable relationship between father and daughter, brother and sister, or husband and wife, for example.
But since kinship also covers social connections, it has a wider role in society, says the Sociology Group, noting that kinship:
- Maintains unity, harmony, and cooperation among relationships
- Sets guidelines for communication and interactions among people
- Defines the rights and obligations of the family and marriage as well as the system of political power in rural areas or tribal societies, including among members who are not related by blood or marriage
- Helps people better understand their relationships with each other
- Helps people better relate to each other in society
Kinship, then, involves the social fabric that ties families-and even societies-together. According to the anthropologist George Peter Murdock:
“Kinship is a structured system of relationships in which kins are bound to one another by complex inter-locking ties.”
The breadth of those "interlocking ties" depends on how you define kin and kinship.
If kinship involves only blood and marriage ties, then kinship defines how family relationships form and how family members interact with one another. But if, as Schneider argued, kinship involves any number of social ties, then kinship-and its rules and norms-regulates how people from specific groups, or even entire communities, relate to each other in every aspect of their lives.