Family exogamy is usually defined by degrees. For instance, saying that one can marry anyone outside of the second degree of a blood-line relationship is a type of exogamy. Family exogamy is characteristic of nonindustrial societies, and is usually based on ties of kinship or moiety rather than on political or territorial lines. Exogamous rules usually characterize unilineal descendent groups, in which descent is reckoned either patrillineally or matrillineally. The marriage prohibition will apply only to one side of the family. Thus, some blood relations will inevitably be available for marriage in this instance.

Society exogamy is practiced by groups that want their members to marry people from outside their culture, village, religion, or/and social class. Sometimes, groups even specify the group they want its members to marry in to.

Walter Heape believes exogamy was derived from the natural desire of male animals to look for their mates outside of their clan or family . Therefore, exogamy is the product of the male instincts and also a natural law. This principle, then, readily carries over into male humans.4

According to Frances and Joseph Gies, marriage has almost always been exogamous. In other words, people have tended to "marry out" of some established degree of relationship throughout the ages. Although some people still relate exogamy to the incest taboo, these beliefs are different, though overlapping. Exogamy is related strictly to marriage, while incest is sex within or out of wedlock. Exogamy prescribes marriage outside of one's own group.

The rules for exogamy have changed often over time. During the early Roman period, for instance, marriage between second cousins was forbidden. The rule was changed a little while later, so even first cousins were allowed to marry.

Romans, barbarians and Christians during the Middle Ages also believed exogamy was a necessity. Marriage and blood must be separated. For instance, Roman law prohibited marriage between partners closer than the fourth degree of relationships to marry during the early Middle Ages. In the seventh century, the Catholic church extended exogamy--it prohibited marriage to in-laws (affines). The church even said "spiritual kin" could not be married (godparents to godchildren).

Jack Goody, a British anthropologist, said extending exogamy was one way the church tried to limit heirs in the aristocracy so the church would have an easier time obtaining aristocratic estates through bequests. A historian named David Herlihy argued that exogamy was another way for the church to prevent the powerful and rich males from taking or keeping more than their share of women. However, both of these ideas are theories that have not been confirmed with documentation.

In the 700's, Roman councils ruled that people were not allowed to marry in the third or fourth degree (which is nieces/nephews or first cousins). When the Roman counting method was replaced with the Germanic method, people were not allowed to marry a descendant of their great-great-great-great-great grandfather. If this rule of exogamy were adhered to, few in the aristocracy would be able to marry at all. Furthermore, people would probably not be able to calculate descendants from that far back.

The Eastern Church never adopted the seventh-degree rule, historian Adhemar Esmein said. However, the Western church probably wouldn't have either if it continued operating under the old Roman-law regions.

The severity of enforcement of exogamy restrictions vary. People can incur capital punishment or mild disapproval for acts contrary to exogamous rules, depending on the customs of the society in which the person resides.

In the past, marriages have been annulled because they are not under the regulations of an exogamous relationship. The archbishop of Canterbury, for instance, annulled a marriage because a couple shared a great-great grandfather. This practice of annulling marriages based on exogamy rules occurred often in history when the male in the marriage sought reasons for divorce.

During the High Middle Ages, it had been realized that some nobles had their family trees redrawn so they could marry within their kinship ties. The nobility sought ways around exogamy rules for many reasons. The primary reason to avoid these rules, however, was to keep wealth within the family. Because most people during this period exchanged dowries and dowers, exogamous marriage meant a significant decrease in wealth for the aristocracy.

At this time, there were also groups that were against societal exogamy. The Jewish clans, for instance, were vehemently against exogamy that led people to marry outside of the Jewish faith. The group was concerned with preserving the traditions of their society.

Near the end of the Middle Ages, people like Martin Luther spoke out about against extreme exogamy (such as how some people couldn't marry anyone related less than seven degrees), leading to another change in exogamy rules. Reformers such as Luther decided that marriage should not be under the jurisdiction of religious institutions. This not only lead to a decrease in the Catholic Church's power, but it also destroyed the higher degrees of forbidden kin relations.

Today, exogamy still plays a role in state-recognized marriage. American society requires family exogamy, but not societal exogamy. In Ohio, marriage licenses have a clause which says a person's marriage partner cannot be "nearer than a second cousin." --Jill Eckert

Bibliography:

Frazer, J.G.Totemism and Exogamy. London, 1968.

Gies, Frances and Joseph. Marriage and the Family in the Middle Ages. New York, 1989.

Heape, Walter. Sex Antagonism. London, 1913.