The ratio of population to sex affects lifespan, competition over women in adolescence is intense and men short lived

It seems that the phenomenon that the life expectancy of male becomes short in an environment with few females and intense competition has already been suggested by studies using various organisms,Harvard Medical SchoolProfessor Nicholas Christakis and his colleagues have revealed.

This is a ratio of reproductive male to female at age reaching sexual maturity (Effective ratio) Is in excess of men, the more they appear, the more they appear. In a society where the ratio of male and female is biased by population policy etc., is it that men's life will be shortened?

Details are as below.Competing for a mate can shorten lifespan

Professor Nicholas Christakis of Harvard Medical School,Hong Kong Chinese University·University of Wisconsin·Northwestern UniversityIn collaboration with the researchers of the researchers, we investigated the relationship between man's gender ratio and lifespan. As a result, men who were extremely male-excessive when they reached the age of reproductive age have an average life expectancy of 3 months shorter than men who were in the normal environment.

"Although it may not seem to be a big deal when it is said to be three months, this is because male-female ratio varies depending on the presence or absence of moderate exercise and the presence or absence of 1 tablet of aspirin administered per day A general 65-year-old man can expect to live another 15.4 years, 3 months of the rest of his life is a fairly significant figure, "Professor Christakis . This research result isDemographyIt is published in the August issue of the magazine.

In my research, I first analyzed the data of "Wisconsin Longitudinal Study" (a long-term research program targeting people who graduated from Wisconsin high school in 1957). After calculating the ratio of male and female of each grade at each high school and comparing various factors affecting life and mortality except for the ratio of male and female, after comparing it, men from overseas high school were able to balance men and women Lifetime is shorter than that of high school graduation,Mortality rateThere was also a calculation result that it was 1.6% higher.

next,MedicareAnalysis of more than 7 million men in the whole country in the United States from similar records of the records of the (National health insurance for the elderly) and census data seems to have yielded similar results. For the reasons of the method, on the contrary, we could not evaluate the longevity of women who were in the environment of female excess in the time of reaching reproductive age in this survey.

In some countries such as China and India, there are concerns about the social impact that abnormal conditions such as the number of males exceeding women by 20% depending on the region, such as selective abortion and domestic movement of the population. The survey results in this survey suggest that such an excessive state of men and an increase in violent crime and human trafficking have already been associated, but this also affects the life span of men.

Although the mechanism of the phenomenon that "the life expectancy of men is shortened in an overly male environment" has not been elucidated yet, Professor Christakis thinks that both social factors and biological factors will be involved That's right. "Anyway, looking for a (mating) opponent is full of stress, and as already demonstrated, stress can contribute to various health problems."

It may be interesting to examine what happens in the case of a person who spent puberty in a boys school or a gender scaled biased class, even in Japan.