There are two interesting views regarding the phenomenon of marrying one's own cousin. Universally, this phenomenon is considered as taboo as inbreeding. However, because this marriage does not take place on the level of first-degree relatives or siblings, there is a view that marrying cousins actually produces stronger offspring.
Apart from marriage with close relatives which can limit genetic diversity and increase the risk of genetic mutations or disabilities, there are other findings that suggest. A study states that being married to cousins plays a role in reproductive success in several groups of people.
The advantages of being married to a cousin
Maintain legacy
If the marriage occurs still in a kinship circle, the greater the retention of inheritance such as property or ownership of livestock, when referring to traditional community life. Family groups from close kinship can mutually defend their resources.
The offspring are stronger
There is research from a psychologist at Carnegie Mellon University Pittsburgh that finds an interesting view. In his study, 46 small community groups were involved to compare the resistance of offspring in groups who married cousins compared with those who were not.
As a result, in community groups whose livelihoods are not hunting or non-foraging societies, their offspring is much stronger. The strong parameter is measured by the number of children who survive in their lineage.
On the other hand, in the community groups that rely on hunting for their livelihoods, fewer children can survive.
Maintain social status
Another consideration that is considered the advantage of being married to a cousin is being able to maintain social status. This is common in royal or upper middle class groups. In addition, their welfare also helps ensure that their offspring can grow properly and have privileges, even from birth.
The risk of marrying a cousin
Risk of genetic defects
Although it is not inbreeding, several studies have found a risk of genetic defects and mental retardation in the offspring of a married couple who are close relatives. In that study, the researchers found there was a 2-3% risk of offspring having genetic defects, mainly those that affect metabolic processes.
Furthermore, children who carry this genetic problem are at 5% more risk of experiencing serious illness to death in their childhood, especially before turning 10 years of age.
The same disease recurs
Being married to a cousin also increases the likelihood of a family member experiencing the same illness. Not everyone can be lucky, like what happened to comedian Gilda Radner who died of ovarian cancer in 1989.
It wasn't until the end of her life that it became known that Radner had a strong history of other family members who also had ovarian cancer. Call it aunts, cousins, and grandmothers who died from the same disease. Whereas in the wider community who are not married to close relatives, the risk of experiencing ovarian cancer is only 1:70.
Considerations before marrying a cousin
Since there is still a risk of heredity suffering from recurrent diseases to genetic defects due to marriage with cousins, it is important to carry out medical background tracing up to 3-4 generations ago Indeed, this is not easy, especially when someone's memory can be wrong when reminiscing about what diseases their ancestors had suffered from.
However, a large family history of medical background will be very useful. There are several diseases in which the pattern can be guessed. Breast cancer is passed along gender lines. Meanwhile, other diseases such as hemophilia will only affect men, not women.
As much as possible, trace all the ailments your relative has had along the horizontal line of the family tree such as your siblings and siblings of your parents. Then, add the relatives in vertical lines from both sides.