Board Thread:Theories and Speculation/@comment-27541896-20160104042813/@comment-3568954-20160109002843

socially they are cousins. genetically they are half siblings. in social terms we view cousins as a person who is the child of an aunt or uncle. genetically and scientifically speaking they would be siblings. for example scientists when talking about the offspring of identical twins. they say they are half siblings. they don't say cousins. because scientifically they are siblings. if a set of identical twins marry a set of identical twins and each coupling has children the children would be genetically full siblings. so said children could refer to each other as siblings or could refer to each other as cousins.

also in the context of incest. birth defects only occur at maximum 7% of the time. this is with close blood relatives such as full siblings, mother/father etc. 1st cousins have roughly a 3 or 4% chance of having children with a birth defect. and the number bottoms out at 2% chance with Any coupling. no matter how far apart genetically they are. the reason Birth defects occur in the first place is because we are all genetically related. and no two people are no more than 50th cousins.