Accidental incest

Accidental incest is incest that is committed by two partners who do not know they are biologically related. It can occur when two people who are unaware of their biological relationship become sexually intimate. When two related people meet as adults, and become sexually attracted, it is known as genetic sexual attraction. When a biological relationship is suspected, DNA testing may be used.

Artificial insemination with donated sperm may result in accidental incest. Because sperm donation is often anonymous, many people conceived in this manner are usually unaware of any biological half siblings they have. The likelihood of accidental incest is kept low with doctors limiting the number of times that each donor's sperm can be used. Some countries have laws limiting the number of children a donor can father in order to reduce the likelihood.Taiwan allows those conceived by artificial means to receive testing to determine if they are related to a person they are considering marrying.

Other causes may include:

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