More boys are born after wars and scientists call it ‘Returning soldier effect’ – Times of India

Through various statistics and data collected over the years, scientists have noticed a strange trend known as the ‘returning soldier effect,’ where more male children are born during a war. This was first noticed in 1954, during World War II, with regard to white children born in the United States. Ever since, countries that have experienced wars have followed the same trend.
No, this is not some crazy coincidence, but a well-established phenomenon.However, no one has been able to come up with a globally accepted explanation of why this happens or even how. The gender ratio has always tipped more towards males, with around 104 boys being born for every 100 girls each year.
A report points out that soldiers who returned from war fathered a record 1.1 million children in 1920, which is the highest for the century. This holds true not only for Britain or Wales, but also for countries like France, Germany, Austria, Belgium, Denmark, and the Netherlands, which saw an increase in the ratio of newborn boys to girls in the years following the world wars.
However, Pastor JP Süssmilch noticed this trend as far back as the 1700s. He went through parish registers and found that more boys are indeed born than girls around a time of conflict or war. He reasoned this as divine intervention, believing that God was balancing the scale by making up for the number of men who died in the war. This theory, however, did not stand the test of logic and science.
Another theory is based on a fascinating report: among British soldiers, those who died on the battlefield were shorter in height than those who survived and returned home. On average, the surviving soldiers were one inch taller than the fallen soldiers. According to psychologist Satoshi Kanazawa, taller people are more likely to have sons than shorter parents. This theory implies that there is a connection between the excess number of boys born during and immediately after the world wars and taller men participating in procreation.
Statistician Bill James offers another theory, which depends on the time of conception. If a woman gets pregnant earlier in her cycle, she has a slightly higher chance of giving birth to a boy. When soldiers return from war, they often engage in sexual activity, which may lead to women getting pregnant earlier in their cycles. While these variations are almost negligible in individual cases, they can make a significant difference when looking at hundreds of thousands of pregnancies.
These are mere theories, as we have yet to agree on why such a pattern exists globally. More research and study in this field may help in reaching a conclusion in the future.