Studies have found that women always live longer.

A new study shows that men don't live as long as women, and so do their primate relatives. In this study, the researchers observed the data of six modern and historical human groups from different countries. The researchers found that "although human life expectancy has greatly improved in the past century, the differences between men and women have not narrowed," said Susan Alberts, a biology professor at Duke University and a co-author of the new study. The researchers did find that women live longer than men in different groups of people. For example, the biggest difference in life expectancy between men and women in the studied population is in modern Russia, with a difference of about 10 years. The differences found in other populations are much smaller, such as those living in modern Nigeria and India. [Life extension: 7 ways to live beyond 100]

In addition, scientists have found that the life span gap of nonhuman primates is much smaller than that of humans.

In the study, the researchers observed the mortality rate of six different groups of people, which represented the "all-round human experience". Scientists obtained the information of three long-lived people from a large international database named "Human Mortality Database", including the Swedish population of 175 1 to 1759, the Swedish population from 2000 to 2009 and the Japanese population of 20 12.

The researchers also studied the data of three people with generally short lives, including two modern hunter-gatherers, the Haza people in Tanzania and the pain in Paraguay, and the data of the free slave people who immigrated from the United States to Liberia between 1820 and 1843. The researchers observed data collected from six wild populations, namely West Faka, Muric, capuchin monkey, gorilla, chimpanzee and baboon, and the number of each population ranged from 400 to 1500. Finally,

The researchers also supplemented their data about human beings and found a smaller data set from another 65,438+06 human groups, including people from Russian, China, Indian, American and other countries.

This study has produced three main findings: First, among the long-lived human groups, such as modern Japan and Sweden, the average life expectancy of people is quite consistent, which means that the age of death in different countries is quite similar: most of the deaths in these countries occur between the 70 s and 90 s of adults, while the life expectancy of other primates is much shorter and quite different.

Second, the difference in life span between people living in industrial society and hunter-gatherer society is greater than that between hunter-gatherer and non-human primates. Researchers found that people living in industrial society live 30 to 50 years longer than hunter-gatherers, but hunter-gatherers only live 10 to 30 years longer than nonhuman primates.

Third, the researchers found that women's life expectancy "tends to be longer than that of men, with little change". [wonder woman: 10 Interesting facts about women's bodies]

According to research, among all people, the oldest is often a woman. But for non-human primates and short-lived human groups, men seem to have a relatively small disadvantage in life expectancy.

Researchers say the reason for this difference between men and women is not clear. But the researchers wrote in their research that this difference exists in many different human groups and non-human primates. The researchers wrote in their research that one possible reason for KDSP and KDSP is that "humans take more risks", alberts told Life Science. She said that if men's life expectancy is shortened, this risky behavior can explain the gap between men's and women's life expectancy and the greater variability of men's death age compared with women's death age.

Another possibility, Albert said, was that testosterone played a role. She said that high levels of testosterone in men may damage their immune system, thus affecting their life span.

This study has several limitations. For example, the sample size of non-human primate population is relatively small. The researchers pointed out that,

This study was published in today's Journal of the National Academy of Sciences (165438+1October 2 1).

Originally published in Life Science.