According to researchers, couples who have girls are more likely to divorce as female embryos are able to withstand stressful pregnancies.
The findings of this research are in contrast to the results of previous studies which had suggested that the higher rates of divorce which can be seen amongst the parents of girls could be down to men preferring boys and daughters putting more of a strain on relationships.
This most recent research, carried out by academics in the US, has discovered that parents whose relationship is already in trouble are more likely to have girls than boys.
This is likely to be because female embryos are tougher than their male counterparts and are better equipped to withstand the strain put upon them whilst in the womb by a mother who is distressed because her relationship with the father is floundering.
Dr Amar Hamoudi, assistant professor of public policy and economics at Duke University in North Carolina, said: “Girls may well be surviving stressful pregnancies that boys can’t survive.
“Thus, girls are more likely than boys to be born into marriages that were already strained.”
There has been a popular misconception that fathers prefer boys and are more likely to stay in marriages when they have sons but Dr Hamoudi argues that: “Many have suggested that girls have a negative effect on the stability of the parents’ union. We are saying, ‘not so fast.’”
Dr Hamoudi highlights the robustness of female embryos, combined that girls and women generally tend to be hardier than boys and men over the course of a lifetime.
Researchers analysed date from a sample of people living in the US from 1979 to 2010 and found that women who reported experiencing higher levels of marital discord were more likely to give birth to girls than boys during the years that followed.
“Population studies typically begin at birth. Yet if demographers and other social scientists want to understand fully how family dynamics affect populations, they need to consider the months before birth as well.
“It’s time for population studies to shine a light on the period of pregnancy. The clock does not start at birth,” added Dr Hamoudi.