Flick through any pregnancy manual, search any site and visit any forum and you'll find reference to "nesting" - the frenzied tidying, sorting and de-cluttering that generally happens during an expectant mother's third trimester.
Often put down to "crazy pregnancy hormones", the behaviour is also described as "primal" or "instinctual."
"The need to nest can be as real and as powerful an instinct for some humans as it is for our feathered and four-legged friends..." reads pregnancy bible What to Expect When You're Expecting," which also claims that for some women it's subtle and for others it's more "dramatic, sometimes irrational and often funny."
But is the urge to nest during pregnancy actually biological, or is it yet another way for women to get lumped with more housework? One expert believes it's the latter.
i’ve already reached the nesting stage of pregnancy... i wanna deep clean everything and rearrange my whole room but i could hardly even walk and my waist down is so sore😫— maranda🤰🏽 (@maranda_rios) March 6, 2020
In a new paper published in Women's Studies International Forum, UK researcher Dr Arianne Shahvisi writes, "Toward the end of my twenties, my social media feeds began to present the pregnancies of peers, their ballooning bumps depicted alongside updates on their daily experiences and challenges." As she watched their pregnancy journeys, Dr Shahvisi noticed her friends reporting an "urgent compulsion" to clean and tidy.
But while the urge to spring clean ahead of the birth of their children made practical sense to Dr Shahvisi, when she explored the behaviour more closely, she found it was usually presented as an "evolutionary adaptation" caused by hormones.
Looking at the reams of advice available to pregnant women online, including Australian site Pregnancy, Birth and Beyond, Dr Shahvisi found that, "while almost all information articles on nesting make reference to this biological basis, none cite any specific scientific study".
"There seems to be an expectation that the causal link will be obvious, and a strong reliance on a seemingly common-sense piece of pregnancy folklore," she notes.
And what about men?
While Dr Shahvisi discovered that nesting was sometimes mentioned in relation to expectant fathers it was highly gender-stereotypical, differed markedly from nesting behaviours in women and not assumed to have a biological basis. Rather than scrubbing the floor and stocking the pantries, dads were more likely to "find themselves preparing for many a housebound evening by investing in upgraded cable, bigger televisions or other man-cave luxuries."
Most importantly, however, evidence for a biological basis for nesting was sorely lacking. In fact, only one study investigated the existence of nesting behaviours in human beings during pregnancy, a questionnaire comparing non-pregnant and pregnant women, which Dr Shahvisi describes as having "significant problems.
As such, Dr Shahvisi claims that linking women to housework through biology is "worrying".
"It threatens to entrench the widespread inequality in unpaid domestic labour," she says, adding that women do not do more housework because they are better-suited to it. "They do more housework because they have less power to object, and have therefore been burdened with more than their share of work that is repetitive, dirty, and invisible ..."
She says traditional nesting tasks such as cleaning and tidying are particularly "gendered household chores" as women are judged more harshly by peers for unclean, untidy houses than their male counterparts.
"Women still do the lion's share of domestic work and reproductive labour throughout the world," Dr Shahvisi writes. "In France, Germany, the UK and Australia, men spend half as much time on housework as women, and in Sweden, which is so often celebrated for its progressive gender roles, men spend just 71 per cent of the time women spend on housework."
And while Dr Shahvisi notes that the overall trend is towards men progressively contributing more time to housework, "their participation in more stereotypically feminine tasks is making much slower progress."
With all of this in mind, if nesting isn't biological, then what is it?
According to Dr Shahvisi there are a number of compelling social explanations for tidying hundreds of onesies, and making sure the nursery is Instagram ready.
"Nesting behaviours are pragmatic and reasonable in late pregnancy, when the reality of the imminent life changes becomes apparent and women start to make preparations in light of inevitable restrictions on their time and energy once the infant is born," she notes, adding that as many women begin maternity leave in the third trimester it makes sense that the cleaning and scrubbing occurs then, too.
But she also argues that pregnancy is a time where women are under increased "social surveillance" when it comes to their perceived gender-appropriate domestic duties, with social pressure to have a clean, tidy house and a "child-appropriate living environment."
And her conclusion is clear: "[Nesting] behaviours are not good candidates to be explained via biological explanations, especially in the absence of a persuasive body of evidence."
If that's the case, what can we learn from this?
Well, a number of things really. If you've found yourself with more of an urge to binge-watch Netflix than scrub the kitchen cupboards then don't feel guilty. Rest up and enjoy the time to yourself. But if you're reading these words before you Marie Kondo your wardrobe, know this too - it's far less likely to be "crazy" pregnancy hormones fuelling the spring clean than it is unfair - and outdated - social pressures and expectations on women and mothers.
As Dr Shahvisi writes, "Even if nesting behaviours are ultimately attributed to a social explanation, that need not detract from the experience being felt as a compulsion. Social forces are just as capable of compelling us to behave in certain ways as are biological forces."
So feel free to put the mop away.