In belligerent countries, male-to-female sex ratios at birth increased during and shortly after the two world wars. This phenomenon is known as the “Returning Soldier Effect”. Nobody has been able to explain it.
fact
In belligerent countries, male-to-female sex ratios at birth increased during and shortly after the two world wars. This phenomenon is known as the “Returning Soldier Effect”. Nobody has been able to explain it.