Blaming girls for the failure of their parents' marriages probably won't be received very well. It's a lesson The Economist learned over the weekend, when an article they published drew heavy criticism on twitter for doing precisely this.

Over a decade ago, two researchers Gordon Dahl, from the University of California, San Diego and Enrico Moretti of the University of California, Berkeley, analysed American census data and reported some interesting results. Men were more likely to marry – and stay married to – women with whom they had sons, rather than daughters.

The data also indicated that men were more likely to propose to their partners if, during the pregnancy, they discovered they were having a boy. They were less likely to get a divorce if their firstborn was a son rather than a daughter. And, when it came to custodial arrangements after divorce, men with sons were more likely to be awarded custody of their children.



The findings were published in Review of Economic Studies in 2008, in an article entitled, "The Demand for Sons".



READ MORE:

* Why my daughters don't wear pink

* When you're not a 'boy mum'

* 'We're expected to be perfect'

Reuters/ JONATHAN ERNST The Obamas' marriage seems quite stable despite having a daughter as a first born.



Reflecting on the data – and more specifically the effect of having a girl on family structure and "fertility behaviour", the authors noted that the number of children is significantly higher in families with a firstborn girl. "Our estimates indicate that first-born daughters caused approximately 5500 more births per year, for a total of 220,000 more births over the past 40 years. "

"The weight of the evidence," the authors conclude, "supports the notion that parents in the US favour boys over girls."

The controversial study resurfaced a few months ago when – in an attempt to understand the results – journalist Emily Bobrow interviewed dads about their experiences raising sons and daughters. In her piece, It's a boy thing, Bobrow explained that while women are generally "agnostic" when it comes to the gender of their babies, men tend to prefer sons.

Why?

Bobrow cites Sean Grover, an US psychotherapist, who believes men often feel less intuitive as parents than women and find it harder to connect with their kids.

"Fathers also like to see themselves as "the fun dad who takes their kids places," Grover says. "Mothers often get stuck with the lion's share of routine child care – all the cleaning and feeding and whatnot – whereas fathers tend to swoop in for more recreational experiences."

It's a generalisation that's highly problematic and yet - as Borrow argues - it ties in with the reported "negative" impact daughters have on marriage. Bobrow speaks to marriage and family therapist, Vicki Botnick, who admits that while her clients don't come into her office saying, "I have a girl and I'm disappointed and it is affecting my marriage," she notes that – from her experience – men with sons are often "more involved and proactive." This, in turn she says, impacts how mothers feel.

Drawing on her own experience Botnick adds, "I have two daughters. When I asked my husband if he thinks this made a difference in how much he helped out, he said, 'Yeah, I probably would feel more of a sense of responsibility if we had a son.' It actually hadn't even occurred to me before."

Bobrow subsequently concludes, "If sons make fathers feel more useful, and leave mothers feeling more inept, it makes sense that they are more likely than daughters to glue couples together."

Over the weekend, The Economist tweeted the article along with the caption: "The key to a successful marriage? Not having daughters." As you can imagine, it didn't go down too well.

One tweeter shared a link to a 2014 article from the journal Demography, which provided an alternative explanation for the original findings. Entitled "Do Daughters Really Cause Divorce? Stress, Pregnancy, and Family Composition," the authors note that while "provocative" studies have reported that marriages producing firstborn daughters are more likely to end in divorce, it's not necessarily due to fathers' preference for sons.

They write, "Our study explores the potential role of another set of dynamics that may drive these patterns: namely, selection into live birth." Female embryos, they explain, are more robust – and therefore more able to withstand stresses to pregnancy such as relationship conflict.

"Many have suggested that girls have a negative effect on the stability of their parents' union," said co-author and sociologist Amar Hamoudi in a statement about their findings. "We are saying: 'Not so fast.' "

The study found that women who reported higher levels of marital conflict were more likely to have daughters in years to come, rather than sons.

"Girls may well be surviving stressful pregnancies that boys can't survive," Hamoudi said. "Thus girls are more likely than boys to be born into marriages that were already strained."