There are certain statistics that indicate that mothers are physiologically much harder to bear sons than daughters. And this applies to both intrauterine growth of the fetus, and the postpartum period of development of the child.

Some scholars believe that, given these characteristics, parents should manage the sex of their offspring born in response to the readiness of the mother's physiological resources. Thus, one can maximize their reproductive success.

In agricultural, meager food tribes living in southern Ethiopia, there is a pronounced relationship between the sex of the child and the diet of the mother.

The effect of the muscular mass is quite remarkable: in women with well-developed biceps and triceps hands - which are 25% higher than the average statistical rate, are twice as likely to give birth to a boy than those whose strength of arms is 25 percent below the norm of medicus. en.

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