Among people who study such things, it’s broadly agreed that in societies with more sexual equality, everyone’s happier and healthier: the women, unsurprisingly, but also the men. (It’s not quite unanimous, but it’s close enough to be added to the list of Reasons We Should All Move To Scandinavia, now hundreds of items long.)

Even so, I was surprised by the recent finding that both men and women sleep better in more equal societies, too. For women, that’s because they get to offload some of the burden of rising at 2.45am to settle a screaming baby, or waiting up until midnight for a teenager to get home. In more traditional countries, the rationale is that women in heterosexual relationships should do all that, because the man – being the main breadwinner, or perhaps wanting to think of himself that way, even if he isn’t – needs his sleep to keep the family provided for. Yet what actually happens in such places, the researchers found, is that men sleep fitfully, too, because they’re worrying about job security and household finances. Plus, they may well be staying up late, or getting up early, in order to work.

There’s an intriguing point here about why, precisely, strict stereotypes cause so much trouble, aside from the basic ethical point that sexism is unjust. The more rigid the expectations attaching to each member of a family (or any group, presumably), the less resilient the resulting group as a whole, because it’s less able to adapt to shifting circumstances. From an individual woman’s perspective, it may be exasperating to be obliged to get up through the night, every night, for a baby. But from the group perspective, it’s also less sustainable: distribute the burden more equally, and the whole family can keep going longer, avoiding burnout. Likewise, when there’s more workplace equality, the task of earning a living gets distributed more evenly, so more hours can be worked, and more money earned, without any single member stretching the limits of their capacity for work – and without a single job loss eliminating a household’s entire income.

There are emotional gains, too, from not being the sole person in charge of anything. If it’s your job, and your job alone, to see the kids through the night, or keep the money coming in, you naturally feel as if you can’t put a foot wrong; share the burden even slightly, and you’re no longer in such an all-or-nothing situation. (What nobody tells you is that tending to a baby in the small hours can actually be an otherworldly joy, provided – and this is key – you don’t have to do it every damned night.)

Besides, we’re simply not designed to perform one role, unremittingly. Karl Marx famously looked forward to the abolition of the distribution of labour, when he might be free “to hunt in the morning, fish in the afternoon, rear cattle in the evening, criticise after dinner, just as I have a mind, without ever becoming hunter, fisherman, herdsman or critic”. Marx didn’t give much thought to parenting, but the point’s still a good one: forcing people into rigid little boxes may serve someone’s agenda, but not our own. We’re bigger than that.

Read this

Helen Russell’s The Year Of Living Danishly is a funny and nuanced account of a Londoner’s life in one of the world’s most sexually egalitarian – and happiest – societies.

oliver.burkeman@theguardian.com