sex ratio and war

If you remember the statistics I send about Iranian population, there was a category exhausting sex ratio in different age groups.

Sex ratio:
at birth: 1.05 male(s)/female
under 15 years: 1.06 male(s)/female
15-64 years: 1.04 male(s)/female
65 years and over: 0.98 male(s)/female

I want to draw your attention to the ratio at 15-65 years age group.
Except over 65 that the ratio is low which is due to physiological differences in men and women in all the rest the ratio is higher than one. But in a comparison between the 15-65 y group and the rest this group has a lower ratio.

The following graph is very interesting.



As you can see the sex ratio shows a sudden drop in 1360 and 1365 which are the war period.

This effect comes from the war. It is shown in different countries sex ratio drops during wartime . It is suggested that it is due to the less tolerance of male fetus in unusual conditions like stress.

reference: J Epidem Commun Health 2002;56:622-623
M.K.