Difficult period was born boy body better

Technology channels () message: United States scientists study found that in difficult times-born boy in their lives are dominant, average life expectancy than in social stability and prosperity period was born boy.

This study on previous concluding complement, that is in distress period, pregnant women in male-child ratio as female abortion is more likely. Responsible for the study of United States University of California at Berkeley School of public health, by Ralph · Catalano said that research has shown that this kind of male fetus miscarriage trend has the role of the survival of the fittest. United States National Academy of Sciences magazine published the results of this study also confirmed the biologists of the long view: man is a little weak in both sexes.

Catalano and her colleague Tim? Bruckner to previous research conducted a study in greater depth. Previous research has shown that in areas such as recession, depression and natural disasters, and other difficult period, the boy's birth rate will decline. They adopted Sweden's data, as Sweden has established a dating back to the year 1751 births, life and death information database. Demographers think, although there is no other region more detailed information, you can also match the database on the global human situation.

The world average of male and female birth ratios of about 105, 100, but in General, died at the young age of men are more likely to wait until the male and female adults, women and men have been broadly balanced. But in difficult times is not the case, there are two contradictory theories to explain its causes. A view that is in the pregnant women under pressure produces a hormone cortisol, a hormone will harm the fetus and fetal harm of miscarriage. Catalano, because male fetus more fragile than female fetuses, they are more vulnerable. The second theory holds that cortisol often make male fetus kicked his legs, a strong enough for FM, possible weak male child, the mother's body will be spontaneous abortion.