It’s been constantly proven that nine months after a major disaster, there is a spike in the number of babies born in the area where it happened. There’s nothing like facing the prospect of death to drive you to pro-create right? The Great East Japan Earthquake of 2011 has brought an even more interesting “phenomena”: there have been significantly more female babies born in the two years since the disaster.
Researchers at UC Berkeley found out that there was a big dip in the percentage of the number of boys born in the districts nearest the epicenter in the Tohoku region while the districts far away had no significant change. There have also been similar findings in other areas where disasters occurred like in L’Aquila, Italy where an earthquake also happened in 2009. Generally speaking, boys tend to have more problems shortly after birth, like being born premature or having low birth weight. The study tried to find out as well if the ratio shift occurred at conception or after; whether there were fewer boys conceived at the time of the disaster or if more boys were miscarried after the earthquakes. They found out that both effects happened in the case of Japan, both greater male miscarriages and fewer male conceptions.
One theory for this occurrence is that it is because of the hormone called human chorionic gonadotropin. According to Ralph Catalano, the head of the study from UC Berkeley, this hormone protects the fetus from the mother’s immune system that have a tendency to attack and cause a miscarriage. The weak male fetus make less of this hormone and so are prone to be miscarried. Another theory is by William James from University College London who said that during stressful times, men produce less testosterone and so it affects the number and quality of sperm produced that carry the Y-chromosome. Whichever the case, the next generation of Japanese, at least in the Tohoku region, might just very well be the “girls generation”.
[ via Telegraph ]