Marriage Systems


Marriage is a ubiquitous feature of human kinship and social organization and probably developed very early in the course of human social history. Widespread functions of marriage in human societies can be associated with several cultural universals:
  1. parental responsibility for long term infant nurturing and education,
  2. social regulation of sexual competition,
  3. organization of sexual divisions of labour,
  4. assignment of individuals to social groups and statuses, and
  5. the formation of intergroup alliances and exchanges.
Yet in spite of these general features, different cultures have developed a fascinating array of regulations and customs that determine prohibitions and preferences for marriage partners as well as expectations between spouses and in-laws.

The widespread occurrence of marriage is explained by competing theories and is probably influenced by a number of different causes. In the discussions that follow, I adopt a single emphasis through the use of alliance theory, formulated by Claude Levi Strauss. As the term suggests, this perspective considers marriage as a method of widening the range of social cooperation through the relations that develop between people and their affines (in-laws), whose friendship and support is often as important as those of consanguineal kin. I prefer this perspective because it helps to integrate much disparate material around a common theme.

Basic Regulations:
Rules of Exogamy and Endogamy.

The basic constants and variations in the organization of marriage and affinal relationships have their origins in the patterns of exogamy (out-marriage) and endogamy (in-marriage). These institutions establish categories of kin and other social identities between whom marriage is prohibited, allowed, preferred and prescribed.

Exogamy and Incest Taboos

All societies have rules of exogamy, closely related to incest taboos, which specify the ranges and categories of relatives who are considered forbidden marriage and sexual partners. These are always the most closely related biological kin, and prohibitions on sexual relations and marriage between parents and children and brothers and sisters are universally applied. Most societies also extend these restrictions to other close relatives, but the ranges and categories included vary among societies. Among other functions, basic features and extensions of incest taboos and exogamous regulations force people to extend their circle of contact, cooperation and alliance beyond their immediate circle to link small kin groups into wider social constellations.


Societies are not only concerned with restricting marriages among closely related kin but also on specifying rules that channel individuals into marriages within particular groups or categories. Even in contemporary Western societies, individuals are encouraged and sometimes forced to marry within ethnic and religious groups and consistently express preferences for mates from similar class and educational backgrounds, in spite of our pervasive emphasis on love and individual choice.

According to considerations of exogamy and endogamy, we can represent marriage patterns as determined by a societies concept of social distance as indicated in the following diagram:

The diagram specifies three ranges of relationship:

  1. an inner group of close relatives with whom marriage is forbidden,
  2. an intermediate range of relatives, associates, and allies with whom marriage relations are encouraged and often required, and
  3. an outer range of outsiders with whom marriage or other forms of interaction must be avoided.

© Brian Schwimmer
University of Manitoba
Created September 1996
Last Updated November 1998