Genus and War I riddle: Why more boys are born after global conflicts

But these large -scale changes are hiding an unusual biological trend that seems to be not explained. After major conflicts, a barely noticeable but statistically significant increase in the number of births of men is registered - this pattern is known as "the effect of a returned soldier," Varsity writes. In focus, technology appeared its Telegram channel.

Subscribe to not miss the most info and interesting news from the world of science! Some people explain this spike in birth or divine intervention, but science offers many intriguing explanations. This phenomenon was first recorded in the 1950s by Macmacho and Pu researchers, but it was especially clear after the Second World War, when the percentage of men in the United States increased from 51. 406% to 51. 48%.

Although the increase was insignificant, it was observed in many countries, which suggests that there is a wider biological mechanism that underlies this phenomenon. Given that in the natural ratio of articles at birth, preference is given to men, probably as compensation for the higher mortality of male infants, this unexpected spike in men's birth after the war remains an interesting topic for scientists. Attempts to explain this effect have led to the emergence of competing theories.

One of the hypotheses suggests that higher soldiers had more likely to survive in battle and that high parents are statistically more prone to the birth of their sons. The study published in the Human Reproduction and dedicated to the First World War soldiers showed that the average height of survivors was a little higher (168. 63 cm) than those who died (166. 26 cm).

In addition, the data of a national longitudinal study of adolescent health revealed a correlation between the height of parents and the highest probability of birth of male offspring. Although this theory is intriguing, it has a biological and genetic justification for why height can play a role in both survival and sex. Another theory, known as the "maternal dominance hypothesis", transferring attention to women who remained in wartime.

When men went to war, women often came into traditionally male roles, performing physically hard work in factories or even participating in the support. Some believe that such changes could lead to increased testosterone levels in their body, which could have affected the likelihood of conceiving a male baby. However, the scientific support of the idea that such changes in lifestyle can significantly change the hormonal background or affect the ratio of articles during conception.

The most plausible explanation is associated with the time of conception in relation to the menstrual cycle. The post-war increase in sexual activity, historically confirmed and called "baby boom" may mean that more pregnancies occur at the beginning of the cycle. At this stage, higher levels of estrogen and gonadotrophins, as well as slightly increased pH of the cervix can slightly contribute to the male semen.

Although this effect will be insignificant for a separate pair, at the population level it can explain the observed shift in the birth ratio. Since there is a decrease in birth rates and a change in the reproductive model in modern society, it is unclear whether the "effect of a soldier returned" in future conflicts will remain.

Since facts indicate that modern people lead a less active sexual life than previous generations, biological forces that have once subtly regulated the ratio of articles may no longer function as before. Whether this will lead to long -term changes in the dynamics of the population of the Earth - the question is open, and the answer to it will only give time and long research. Earlier, Focus wrote about a Brazilian mushroom that mummifies its victims.