Exogamy is a social custom which specifies individuals can only marry people outside their own group. This group is usually but not always defined through kinship or family, rather than larger groups concerning religion, race, or social class.
Exogamy is the opposite of endogamy, which recommends marriage within an individual’s own group.
Out-marriage is another name for exogamy.
Exogamy is most commonly seen in societies with clans or moieties. In these societies, descent flows through the father’s or mother’s lineage. Marrying a member of the same clan is viewed as incest.
Many people prefer exogamous marriage because it widens the pool of potential partners. With many more potential mates to choose from, there’s a greater chance people in exogamous societies will find a partner they’re emotionally and sexually compatible with.
Exogamous marriage minimizes the risk that spouses will be genetically related. These marriages can therefore minimize the risk of passing on genetic defects. However, there is still a small chance that the spouses in an exogamous marriage will be genetically related. For example spouses could be genetically related if they were adopted out and were not aware of their bloodline.
Exogamous marriage also increases the size of families. This means there are more people to help out when jobs need to be done, and more people able to provide emotional support during hard times.
There are a couple of disadvantages to exogamous marriage though. This type of marriage does not preserve a pure bloodline, which is preferable to some people. There can also be some adjustment for couples who must learn to relate to a spouse that belongs to a different group.
In exogamous societies, there are usually penalties for entering into endogamous marriages. These may vary from social disapproval to more severe penalties like death.
