A study of the relationship between the birth of boys and girls, from 1838 to the present day, has helped to identify some very curious features. It turned out that in 1919 and in 1944 began rapid bursts of birth rates of boys. This was due to the approaching end of the two world wars, when people had more time for carnal pleasures.
However, there is also a theory that the birth of boys after the world wars is explained by evolution. After all, the victims of these world conflicts are often men, so that their number needed to be quickly filled. However, modern scientists are more inclined to the theory of the frequency of sex.
In their opinion, the sex of the fetus is determined by the level of hormones in its parents at the time of conception. Boys are more likely to be conceived at the very beginning of the cycle. The peak of fertility for a woman is the period two days before ovulation, but if couples have sex very often, conception occurs before reaching this peak in the early phase of the cycle.
Naturally, during the war, women do not have too many intimate pleasures, and if a man does appear in the house, he seeks to fill this gap. The intensity of sex increases, which is what leads to the conception of more boys, experts believe.
Similar statistics showed that the maximum number of girls is born in the most stressful periods of history, for example, after the terrible Japanese earthquake of 1995, or after September 11, 2001 in New York. The researchers found that during stressful periods, women have many miscarriages, the victims of which are boys. If more sex leads to the conception of boys, less leads to the birth of girls. And in times of stress, women and men are not up to intimate pleasures.