Need sacrifice your left testicle for a boy?
17 Oct 2016
It was Procope-Couteau; 18th Century French anatomist had undertook the extreme measure to have a baby boy. “Sacrifice your left testicle for a baby boy” was the historically acclaimed solution for male preferential sex.
Poor husbands are directed to turn their faces eastwards during sex poor women are forced to seduce men over a cocktail prepared with red wine and fresh rabbit’s womb for a baby boy. Sometimes bad weather makes for more baby girls, as does fasting for Ramadan or suffering from morning sickness. Some other times a taste for breakfast cereal may likely bring you baby boys. Occasionally it is also believed that men with more sisters tend to have girls while those with more brothers tend to have boys.
Superstitions continue even in the midst of theory of probability even in this age of incredible cyber universe.
However the chance of having a baby boy is exactly 50:50. Worldwide statistics say, there are around 109 boys born for every 100 girls.
In every species as Charles Darwin studied, there were almost the same number of males and females; the variation was not nearly as wide as he had expected. After failing in the attempt to find out a scientific solution, Darwin conclusively remarked, “…I now see that the whole problem is so intricate that it is safer to leave its solution for the future.”
Back in 1972, Robert Trivers, a renegade scientist together with a colleague, Dan Willard, has developed one of the most famous theories in evolutionary biology. It’s known as the Trivers-Willard hypothesis and it goes like this.
Trivers argues that it arises from the fact that a female invests more in the young, compared to a male who can just have sex and leave the childrearing to the mother. Consider the fact that the most prolific mother in world history was the nameless first wife of a peasant from Shuya, Russia, who lived from 1707 to 1782. In total, local records reveal that she gave birth to 69 children, which is nothing compared to the warrior Genghis Khan, who fathered between 1,000 and 2,000 children before he died in 1227.
Today, Genghis Khan thought to have around 16 million great, great … great grandsons. And Khan is not the only one; a recent DNA analysis revealed at least 10 men from history who have left a legacy comparable with Khan’s, including a Chinese ruler who died in 1582, and the originator of the medieval Uí Néill dynasty in Ireland.
Then there’s the issue of resources. Because they tend to be larger, sons require a lot more food than daughters and in many societies they’ll require more education and money. To produce a son capable of becoming a dominant, high-status male, parents will need to make a big investment.
With these factors in mind, Trivers proposed that in favourable conditions, such as where the parents were high status or food was abundant, it would make evolutionary sense for parents to produce more sons. But in less favourable conditions, natural selection should favour parents who produce more daughters, since females don’t face such fierce competition. Even if they aren’t particularly attractive or socially successful, it’s likely they’ll have at least some children.
Nearly four decades later, economist Douglas Almond found himself poring over Chinese census records to find out what had happened afterwards. But he wasn’t looking at the records of the victims – he wanted to know what life was like for their middle-aged children.
Together with colleagues from Columbia University, he compared the records of those born soon after the famine with information about the province in which their parents were born. Some areas were affected more than others, so the team was able to compare the prospects of those whose mothers had gone hungry with those whose mothers had not.
What they found was alarming. Though the children hadn’t experienced the famine themselves, those from famine-stricken regions were less likely to be literate, employed and self-sufficient and tended to live in smaller homes. Women tended to marry later and men were lucky to marry at all. Finally, across the whole sample, those born to affected mothers were significantly less likely to be born male in the first place. The effect even seemed to carry over to their children, who were also more likely to conceive daughters.
To estimate the size of the effect, remember that worldwide there are around 109 boys born for every 100 girls. But between 1960 and 1963, the number of male children born in China fell to just 104 boys for every 100 girls, a difference of around 5% according to a later study on the famine. The ratio didn’t return to normal until 1965.
We now know that from smoking to war, to climate change, unfavorable conditions predispose women to having more girls. On the other end of the scale, women with more dominant personalities, a diet rich in high calorie foods (such as breakfast cereal), or married to U.S. Presidents tend to give birth to more sons. For billionaire fathers, the odds of having a boy are 65%.
Perhaps it’s time to put the cereal away, leave your testicles alone and accept that, in the end, the chances of having a boy are – and should be – roughly 50:50.