Blood Relations
Marriage between people who are closely connected by blood (consanguinity) has been forbidden by many cultures throughout history.
Consanguinity, literally meaning common blood, describes a family relationship between two individuals and is measured in terms of the degree of consanguinity. The degree is measured by counting the number of steps between two individuals in a family tree; thus, for example, you are one degree from your children; a brother and sister are two degrees apart - one step up to the common parent, another back down to the sibling.
| Men cannot marry their: | Women cannot marry their: |
|---|---|
| Mother | Father |
| Grandmother | Grandfather |
| Daughter | Son |
| Granddaughter | Grandson |
| Aunt | Uncle |
| Niece | Nephew |
| Sister | Brother |
In general, the lower the number of degrees of consanguinity, the higher the risk of inbreeding. Most cultures regard sexual relationships between people with high levels of consanguinity as incest, and forbid marriages between such people.
However, contrary to the view held by many people, there is no legal bar that prevents cousins marrying each other.
