Why modern parents feel more sleep deprived than our ancestors did

Our ancestors probably didn't suffer as much from parental sleep deprivation, leading some scientists to reconsider guidelines for today's new parents to get some shut-eye.

How exhausting is it to be a parent? When one brave soul posed this to a Reddit parenting forum, more than 400 answers flooded in. "Extremely. It's extremely exhausting and it is literally CONSTANT," wrote one respondent, the sentiment echoed by hundreds of others.

There are many reasons why parents feel so bone-crushingly tired today – and not all of them have to do with sleep. For instance, many families raise their children without community support, while parents often have to juggle work with child-rearing. 

At the same time, many caregivers' sleep certainly changes after having children, whether that's due to an infant's middle-of-the-night feeds or a preschooler's penchant for a 05:00 start. 

Given that we've been parenting for as long as humans have existed, it may seem natural to assume parents have been sleep-deprived for millennia, too. But the evidence that we have indicates this likely isn't true. So what did our ancestors do differently – and is there anything we could learn from them?

How much sleep are parents really getting?

In everyday conversation, parenting and sleep deprivation are taken to be synonymous. However, the evidence on just how much sleep parents tend to lose after having a child is mixed and culturally dependent.

One study, for example, found that first-time mothers in Germany on average get an hour less of sleep per night in the first three months after their baby is born than they did pre-pregnancy. Fathers lose a third of an hour. Although sleep duration increased after an all-time low at three months, neither parent had fully recovered their pre-pregnancy sleep after six years.

But the overall difference between parents and non-parents after the post-partum period is not nearly as big as you might believe. On average, the German study, which looked at nearly 40,000 people in total, found that parents who had at least one child under six years old reported sleeping about seven hours per night. Non-parents received just 10 minutes more sleep per night, for women, and 14 minutes more per night, for men.

Meanwhile, data from a 2024 survey in the US found that parents with children under age six are, on average, in bed for between eight and nine hours per night – well within the recommended range. Similarly, a French study, following more than 400 couples in the 36 months after birth, found that both mothers and fathers logged an average of eight hours' sleep or more at all time points (although some individuals slept as little as 4.25 hours per night, others as much as 12).

Of course, this is mostly self-reported data, so people may over- or underestimate their sleep duration, like starting their calculations from when they went to bed and not when they fell asleep, for instance.

But it does, overall, suggest that many parents are getting relatively good amounts of sleep, albeit with a lot of variation. And when researchers examine sleeping patterns in contemporary foraging societies – which is often helpful to try to determine how our ancestors probably lived – results aren't too different. One analysis of three hunter-gatherer societies, for example, found that adults (including parents) spent between 6.9 to 8.5 hours per night in bed. Because they woke frequently, the average of how much they actually slept was between 5.7 and 7.1 hours per night.

Crucially, though, modern parents in industrialised societies consistently report feeling much more tired and exhausted than those in foraging societies. Scientists have been trying to solve the mystery of why that is.

The perception of sleep

In foraging societies, nearly all adults – many of whom are parents – say they're very satisfied with their sleep, says evolutionary anthropologist David Samson, director of the University of Toronto's Sleep and Human Evolution Lab and author of the book The Sleepless Ape: The Strange and Unexpected Story of How Social Sleep Made Us Human. 

Samson spent three months living with the Hadza, a foraging society in northern Tanzania, to study their sleep patterns. "When you go to the Hadza and ask them, 'Is your sleep good or is it bad?', they say 'It's good'," he says.

In contrast, when parents in modern, industrialised societies are asked about the quality of their sleep, they usually give it low marks. In the German study, for example, mothers rated their satisfaction with their sleep 6.57 on a scale of 0 to 10; fathers, 7.03. In the French study, nearly three-quarters of the mothers of three-month-olds said they thought they had not had enough........

© BBC