Comrades who have received nine years of compulsory education all know that the country prohibits marriage between blood relatives within three generations. Such marriages pose great risks as they increase the occurrence of hereditary diseases in the family to some extent, leading to a higher rate of fetal deformities, ultimately impacting family life and even burdening society heavily.
In contemporary society, such occurrences are rare. However, looking back a few years, in an era when people seldom ventured out, many young maidens at the age of first love often found their admirers to be none other than their cousins.
Thus, the love between cousins eventually became a fairy-tale-like relationship, something that parents back then were pleased to witness. In ancient times, marriages were often arranged based on parental commands and matchmakers’ advice. Consequently, cousin marriages were quite common in that era. But why didn’t genetic diseases appear as prominently in those times as they do today?
Impacts of Cousin Marriage
The danger of cousin marriages lies in the fact that both parents share many similar genes, making it easier for harmful recessive genes to be passed on to their offspring. This significantly increases the chances of giving birth to children with low quality or congenital diseases.
According to the World Health Organization’s estimates, each individual carries about 5 to 6 disease-causing genes. When individuals unrelated by blood marry, the fewer shared genes mean less chance of carrying the same harmful genes, thus increasing the likelihood of producing healthier children.
Influenced by Chinese traditions, East Asia has long held the custom of endogamy, forbidding individuals of the same surname from marrying. However, marriage between cousins from different maternal lineages was permissible, especially prevalent among royal families.
Children born into royal families were deprived of the right to choose their legitimate spouses from birth. For them, marriage was merely a form of political alliance; hence, they married those deemed beneficial to their status.
In ancient times, parents’ decisions and matchmakers’ arrangements greatly overshadowed the young couples’ autonomy in marriage. Some even got married without ever having met before, and yet they were bound to spend their lives together.
The advantage of such marriage arrangements is that parents, having navigated society for years, often possessed a more comprehensive understanding than their children. Therefore, their choices typically bore significant practical significance. This meant fewer challenges in real-life compared to freely matched marriages.
However, every coin has two sides. In such a model, parents wielded excessive influence in their children’s marital affairs. If offspring found their true love but faced conservative parents, conflicts between generations were common occurrences.
Moreover, parents in such marriages tended to prioritize the partner’s family background over the marriage itself. On deeper contemplation, the old saying “mutual respect in marriage” in ancient times might have stemmed from this—living together out of duty rather than affection could have been considered the best resolution.
We cannot evaluate the happiness of such marriages. However, one glaring issue was evident – the higher the social status, the more prevalent cousin marriages were.
Reasons for Cousin Marriages in Ancient Times
As mentioned earlier, it was inevitable for aristocratic families to engage in political alliances through marriages, fostering mutual benefits between both families.
Not limited to inter-group marriages, within the same group, families tried to retain their power by resisting external influences. Consequently, many large families unknowingly opted for endogamy as a protective measure against impurity in their bloodlines.
With shared interests in mind, widespread cousin marriages were common. So, how did ancient people reduce the chances of producing deformed offspring amidst such practices, unlike the taboo it is today?
In fact, even in ancient times, the curse of high deformity rates persisted in cousin marriages. Consanguinity led to the transmission of similar genetic factors, preserving many harmful recessive genes which then led to a myriad of congenital or hereditary diseases in offspring.
For instance, towards the end of the Qing dynasty, the rulers faced instances of having no successors. After Emperor Tongzhi’s death without an heir, Emperor Guangxu was adopted as there was no direct descendant.
Still, even with these examples, ancient Chinese cousin marriages did not result in cases like the Japanese imperial family with hereditary spine deformities. Why was this so?
Chinese Favored by Genetics
It may seem that ancient Chinese enjoyed genetic favoritism, but was this indeed the case? The history of intra-family marriages in China was quite lengthy and peculiar. Strictly speaking, ancient Chinese endogamy within families was not exactly cousin marriage.
Firstly, the ancient Chinese upheld a moral code emphasizing that the worst filial act was not having an heir. Although large families practiced monogamy, aristocrats were often allowed concubines.
Consequently, a person might have multiple offspring, varying in blood relations, thus diversifying the family tree and genetic pool.
Such practice lowered the risk of inheriting recessive genetic diseases due to similar genes between generations in intra-family cousin marriages, ensuring better health prospects for future generations.
Secondly, in ancient China, although families practiced endogamy, it was primarily marriage within big clans sharing the same surname. These clans had a significant historical affiliation and substantial population sizes.
As a result, even though descendants shared the same surname, multiple generations had passed, making it less likely for marriages to be considered as cousin marriages.
The final reason—albeit the most brutal one—is the internal power struggles within aristocratic circles. Despite their external grandeur, fierce internal power struggles were rampant, as is evident in the drama “Empresses in the Palace.”
Under such circumstances, the likelihood of miscarriages increased substantially. Consequently, many fetuses perished before birth, reducing the chances of deformed offspring. In an era of severe natural selection, many children born weak were unlikely to survive until the end without establishing remarkable success—ancestors focused more on the successful heirs, unaware of the mix of their same-blood group.
The curse of cousin marriages spares no one, not even noble families. It’s worth mentioning that even non-consanguineous marriages can lead to higher chances of deformed offspring due to maternal neglect and certain lifestyle choices.
After being formally prohibited by law in 1980, cousin marriages became history.
