History Analysis / KissingCousins

Thanks to the discovery of the laws of genetics a fairly modern part of the taboo against cousin marriage is the perception that this form of inbreeding results in heightened risk of offspring with genetic disorders like hemophilia or albinism. A [[http://www.news.com.au/perthnow/story/0,21598,23792218-2761,00.html study]] in Western Australia discovered that while the risk of a serious defect does rise slightly, the change isn't that dramatic (i.e. a 4% risk for first-cousin parents instead of a 2% risk for unrelated parents--roughly equivalent to the risk of birth defects in children conceived by women age 35 and older as compared to children conceived by women under 35) Please note, however, these statistics apply only to first cousins: any couples more distantly related are likely to be as genetically dissimilar as randomly paired individuals from the general population (how many of your third cousins do you even ''know''?).[[note]]On the other hand, getting any closer than first cousins is quite dangerous, because relatedness works on an exponential scale. An uncle-niece pair share 1/4 of their genes as compared to 1/8 for first cousins, and full siblings on average share 1/2 of their DNA.[[/note]] And the first-cousin marriages studied were one-time occurrences, those statistics don't cover [[TangledFamilyTree an entire family tree doing it for generations]] like has been seen in certain [[RoyalInbreeding aristocratic populations]]--repeated, exclusive endogamous marriage is likely to have [[RoyallyScrewedUp more serious genetic consequences]]. And if there's known to be a serious hereditary condition in the shared part of the family tree, it's obviously a bad idea.

Most of the origins of the cousin marriage taboo are not inherently religious; the ancient Hebrew patriarchs demonstrably had no problem with cousin marriage at all (Isaac married Rebekah, his first cousin once removed). The largest Christian denomination, the Catholic Church, allows even first cousins to marry with special dispensation. First-cousin marriage is perfectly fine under Islamic law and some Middle Eastern and Central Asian cultures actively encourage it. Hinduism, Buddhism, Confucianism, and Asian animist traditions have little to say against cousin marriages either.

This was also the case in China, in a historical period analogous to that of feudal Europe; nobles were explicitly banned from marrying ''any'' person that could trace their paternal lineage to the same historical tribe (effectively, anyone with the same family name). This was then extended to all social classes after the unification of the Chinese empire; people bearing the same surname were forbidden to marry even if they were not related at all. However, cousins with different surnames were allowed, and in many cases encouraged, to be paired together to strengthen the alliance between two clans during said period. Linguistic remnants of this tradition may still be found in some areas in Southern China, where the form of address used for one's mother- and father-in-law may also be used to address one's uncle and aunt.

Thanks to the discovery of the laws of genetics a fairly modern part of the taboo against cousin marriage is the perception that this form of inbreeding results in heightened risk of offspring with genetic disorders like hemophilia or albinism. A [[http://www.news.com.au/perthnow/story/0,21598,23792218-2761,00.html study]] in Western Australia discovered that while the risk of a serious defect does rise slightly, the change isn't that dramatic (i.e. a 4% risk for first-cousin parents instead of a 2% risk for unrelated parents--roughly equivalent to the risk of birth defects in children conceived by women age 35 and older as compared to children conceived by women under 35) Please note, however, these statistics apply only to first cousins: any couples more distantly related are likely to be as genetically dissimilar as randomly paired individuals from the general population (how many of your third cousins do you even ''know''?).[[note]]On the other hand, getting any closer than first cousins is quite dangerous, because relatedness works on an exponential scale. An uncle-niece pair share 1/4 of their genes as compared to 1/8 for first cousins, and full siblings on average share 1/2 their DNA.[[/note]] And the first-cousin marriages studied were one-time occurrences, those statistics don't cover [[TangledFamilyTree an entire family tree doing it for generations]] like has been seen in certain [[RoyalInbreeding aristocratic populations]]--repeated, exclusive endogamous marriage is likely to have [[RoyallyScrewedUp more serious genetic consequences]]. And if there's known to be a serious hereditary condition in the shared part of the family tree, it's obviously a bad idea.

Thanks to the discovery of the laws of genetics a fairly modern part of the taboo against cousin marriage is the perception that this form of inbreeding results in heightened risk of offspring with genetic disorders like hemophilia or albinism. A [[http://www.news.com.au/perthnow/story/0,21598,23792218-2761,00.html study]] in Western Australia discovered that while the risk of a serious defect does rise slightly, the change isn't that dramatic (i.e. a 4% risk for first-cousin parents instead of a 2% risk for unrelated parents--roughly equivalent to the risk of birth defects in children conceived by women age 35 and older as compared to children conceived by women under 35) Please note, however, these statistics apply only to first cousins: any couples more distantly related are likely to be as genetically dissimilar as randomly paired individuals from the general population (how many of your third cousins do you even ''know''?).[[note]]On the other hand, getting any closer than first cousins is quite dangerous, because relatedness works on an exponential scale. An uncle-niece pair share 1/4 of their genes as compared to 1/8 for first cousins, and full siblings on average share 1/2 their DNA.[[/note]] And the first-cousin marriages studied were one-time occurrences, those statistics don't cover [[TangledFamilyTree an entire family tree doing it for generations]] like has been seen in certain [[RoyalInbreeding aristocratic populations]]--repeated, exclusive endogamous marriage is likely to have [[RoyallyScrewedUp more serious genetic consequences]].

Some cultures distinguish between ''parallel'' cousins--one's mother's sister's child or father's brother's--and ''cross'' cousins--mother's brother's or father's sister's. Cultures in which a parallel cousin is taboo often regard the cross cousin as the best possible choice of a spouse, since the marriage will strengthen bonds among members of the bloodline and ensure that property remains in the family.

This was also the case in China, in a historical period analogous to that of feudal Europe; nobles were explicitly banned from marrying ''any'' person that could trace their paternal lineage to the same historical tribe (effectively, anyone with the same family name). This was then extended to all social classes after the unification of the Chinese empire; people bearing the same surname were forbidden to marry even if they were not related at all. However, cousins with different surnames were allowed, and in many cases encouraged, to be paired together to strengthen the alliance between two clans during said period. Linguistic remnants of this tradition may still be found in some areas in Southern China, where the form of address used for one's mother- and father-in-law may also be used to address one's uncle and aunt.

!!Genetics
Thanks to the discovery of the laws of genetics a fairly modern part of the taboo against cousin marriage is the perception that this form of inbreeding results in heightened risk of offspring with genetic disorders like hemophilia or albinism. A [[http://www.news.com.au/perthnow/story/0,21598,23792218-2761,00.html study]] in Western Australia discovered that while the risk of a serious defect does rise slightly, the change isn't that dramatic (i.e. a 4% risk for first-cousin parents instead of a 2% risk for unrelated parents--roughly equivalent to the risk of birth defects in children conceived by women age 35 and older as compared to children conceived by women under 35) Please note, however, these statistics apply only to first cousins: any couples more distantly related are likely to be as genetically dissimilar as randomly paired individuals from the general population (how many of your third cousins do you even ''know''?).[[note]]On the other hand, getting any closer than first cousins is quite dangerous, because relatedness works on an exponential scale. An uncle-niece pair share 1/4 of their genes as compared to 1/8 for first cousins, and full siblings on average share 1/2 their DNA.[[/note]] And the first-cousin marriages studied were one-time occurrences, those statistics don't cover [[TangledFamilyTree an entire family tree doing it for generations]] like has been seen in certain [[RoyalInbreeding aristocratic populations]]--repeated, exclusive endogamous marriage is likely to have [[RoyallyScrewedUp more serious genetic consequences]].