introduction
Everyone may have a common illusion, that is, the ancient laws of our country did not prohibit the marriage of close relatives, but in fact, the laws of most dynasties stipulated that close relatives could not intermarry, for example, the Book of Wei recorded: "It is a marriage of Xia Yin who does not feel the same family, and the Zhou Dynasty will never marry with the same surname." The meaning of this sentence is that in the Zhou Dynasty, marriage between the same surname was not allowed. Later, the Qing Dynasty stipulated more detailed regulations, but these regulations were not binding on the people, especially in the Ming and Qing dynasties, intermarriage between close relatives was very common.
China's current marriage law does not allow close relatives to marry, and the main reason for this is that, in addition to social and ethical issues, there are also genetic problems that may arise from intermarriage between close relatives. What are close relatives? According to the provisions of China's Marriage Law, relatives who have a common blood relationship within three generations or less are called close relatives, and men and women within this range cannot intermarry. However, in ancient times, intermarriage between close relatives is a very common thing, for example, in "Dream of the Red Chamber", Lin Daiyu's mother and Jia Baoyu's father are brothers and sisters, Jia Baoyu and Lin Daiyu are close relatives; and Xue Baochao's mother and Jia Baoyu's mother are sisters, Jia Baoyu and Xue Baochao are also close relatives, and the two of them eventually married.
▲ Stills of "Dream of the Red Chamber"
01
So why did the ancients want to intermarry between close relatives? This is related to the clan system in feudal society, the so-called kinship is to stabilize the family power through marriage. Moreover, the women of large families in ancient times generally rarely went out, and they had met their cousins, and the families of both sides were more familiar. Therefore, in ancient times, many large families would choose close relatives to marry, but generally they would not marry with the same surname, that is, cousins did not often intermarry.
Close marriage was very common in ancient times, for example, Lu You and his wife Tang Wan were cousins, the relationship between the two was originally very good, but because Lu You's mother did not like Tang Wan, the two eventually had to break up, Lu You also wrote in the "Phoenix": "Although the mountain alliance is there, the Jinshu is difficult to trust", which shows its sadness and sadness.
▲ Lu You, Tang Wan stills
02
There was also Chen Ajiao, whom Emperor Wu of Han married, who was also his cousin. In addition to brothers and sisters, there are many examples of relatives in ancient times, such as Princess Chen Guo, the daughter of Yelü Longqing, who married her uncle; and Yang, the nephew of Tang Xuanzong, said that she married Tang Xuanzong's daughter Princess Weiguo.
But you may find that while marriages were common in ancient times, there are few records of children born after marriage with intellectual or other genetic problems. Experts say we'll take a closer look at the details. In general, offspring from intermarriage are much more likely to have defects in areas such as intellectual disability than in normal marriages. The reason why so many close relatives married in ancient times, but there are not many, mainly for the following reasons.
▲ Ancient wedding stills
First, the marriage of close relatives of the general ancients is usually between first-class cousins, and in such kinship, the genetic similarity is not particularly large. So their offspring have a lower probability of developing significant defects, about 1 in 4. The families of the ancients generally had many children, four or five are counted as few, and the probability of defects in such data is even lower. And according to the technology and medical conditions at the time, there are very few children with birth defects who can successfully survive, and they will naturally not pass on the defective genes to the next generation.
03
Second, in ancient times, it was polygamy, especially in some larger families. Therefore, the relationship between relatives is more complicated, even if it is a cousin, it also contains multiple intermediate relationships. Most of them are relatively distant in blood relations, and many are only nominal close relatives, and in terms of blood relations, they are no longer within three generations.
▲ Cousin cousin in film and television dramas
Third, due to the economic situation and social structure, the affordability of families in the feudal era for the disabled group was very low, and there were no restrictions on having children. So once many families find that their newborns are congenitally disabled or have intellectual problems, they will kill them. This situation also occurs in a large number of female infants, due to the serious idea of son preference in the feudal era, many female infants are abandoned or drowned at birth. In this case, the government will not bother at all.
Fourth, the mortality rate of infants in ancient times was quite high. Due to the limitations of scientific and technological level and living conditions, the life expectancy of ancient people is generally not long, and the average life expectancy in ancient China is about thirty or forty years old, of which there are a large number of babies who have died prematurely. In ancient times, women generally married earlier, and they gave birth to children like a ghost door, not to mention the newborns who were already weak.
▲ Ancient baby stills
Even if it is not the offspring of intermarriage between close relatives, it is very easy to die prematurely, and almost every household has children who die prematurely. If there is a physical defect due to intermarriage between close relatives, such a baby is even less likely to survive.
epilogue
In fact, there is also a probability that the offspring born of defective offspring by the marriage of close relatives also has a probability, not that after the marriage of close relatives, the offspring born will be defective. It is just that in modern society, since the disadvantages of marriage between close relatives are known, of course, they must be avoided. Coupled with the social and ethical problems arising from consanguineous marriages, most countries prohibit intermarriage between close relatives.
Resources:
Book of Wei
"The Phoenix"