In fact, this data is an average data. If you die of natural aging, it is not uncommon to live to 50 years old, mainly because the following factors reduce the average life expectancy.
1. Backward medical care In ancient times, there was no complete medical system and no modern means of seeking help, especially the lack of scientific reproductive knowledge, which led to a very high infant mortality rate, even at birth. Children who can live to be over ten years old are simply lucky!
Not only children, but also adults infected with diseases can easily lead to death. There were no advanced diagnosis and treatment methods in ancient times, and many diseases were fatal to human beings.
At the same time, ancient people lacked correct treatment methods and isolation knowledge for infectious diseases. Once a plague occurred in ancient times, it often caused a miserable scene of no one in a hundred miles and chickens crowing. Until modern times, infectious diseases such as COVID-19 were still a serious threat, not to mention the ancients.
Second, since the beginning of human society, wars have occurred frequently. From the earliest war between tribes, to the hegemony of various countries in Xia, Shang and Zhou Dynasties, to the Spring and Autumn Period and the Warring States Period, every dynasty change represents thousands of people killed in the war.
Historically, dynasties without wars are extremely rare, border wars have never been reported, and there will be large-scale wars every hundred years, not to mention the troubled times like the Five Dynasties and Ten Countries.
The war consumed a large number of people, resulting in a sharp decline in population. The war consumed all the young and middle-aged laborers, and also led to a large number of abandoned fields. Agricultural production, especially grain production, was greatly reduced, resulting in a serious famine, which further led to a decrease in population and a decrease in average life expectancy.
Third, famine continued. Ancient times was an agricultural society, lacking advanced agricultural technology, not to mention chemical fertilizers, pesticides and aquaculture. Eating purely by the weather, food has always been a decisive factor restricting population growth in ancient times.
During the long feudal dynasty, famine occurred almost every year. It is well documented that at least once every ten years, famine swept through one province, several provinces and even the whole country.
First of all, due to climatic reasons, rainstorm, drought, locust plague, flood and so on. It often happens that ancient humans lacked advanced machinery and technology, which led to crop failure and large-scale reduction of grain production.
On the surface, famine is not as bloody as war, but its impact on social economy and population development is more destructive than war. Once a large-scale refugee is formed, it is absolutely a disaster for a dynasty.
The plague after the catastrophe and the civil strife after the catastrophe were almost the curse that the feudal dynasty could not get rid of. For thousands of years, there are only a handful of days when ordinary people can really eat enough.
Conclusion: Another reason for the low life span of ancient humans is the marriage of close relatives, not only in China, but also in foreign countries. Don't you know that many European monarchs are relatives? The improvement of the average life expectancy of the population is conducive to the progress of medicine and health, to the peace for a long time, and to the development of agricultural science and technology.