It's an age-old question: When a child wakes at night, which parent should get up?
Some people tally their previous awakenings to work this out ("I got up twice last night, it's definitely your turn"), while others base it on who has 'more' to do the next day.
Then there are those who (*cough*) simply pretend to be asleep, in the hope the other parent will get out of bed first.
Now new findings, published in the Journal of Sleep Research, suggest another way to make this decision: depending on the parent's gender.
According to the research, staying up all night harms a woman's working memory - but not a man's.
The findings were based on research that involved 24 young adults - 12 men and 12 women.
Each participant completed two memory tests taken a week apart.
They completed the first test the morning after a full night's sleep, while the second test was done the morning after not sleeping at all.
The researchers found that skipping a night's sleep had no impact on the working memory of men.
Women, on the other hand, had a reduction in working memory when sleep deprived.
So does that mean dads should yank themselves out of bed when their kids cry at night, as they may cope better the next day than mums?
Sleep consultant Dr David Cunnington, co-founder of Sleep Hub, doesn't think so.
He says he's "cautious" of interpreting the results of such a small study and doesn't believe these results are conclusive.
Health Psychologist Moira Junge, who is on the board of the Sleep Health Foundation, agrees.
Besides, she says, this study looked at how people coped with missing one full night of sleep, as opposed to what parents have to deal with - which usually involves getting up multiple times throughout the night.
While this study found that women's working memories were impaired by sleep deprivation, Moira doesn't believe women cope worse with lack of sleep.
Regardless of who copes better in such circumstances, the truth is, if you're sleep deprived you're likely to feel worse for wear the next day.
But there are ways to help power through the day, Moira reassures.
The first step is to acknowledge the issue - without harping on it.
"One of the worst things would be to dwell on it and focus on how awful it is to be so tired," she warns.
Instead, she says you're better off trying to normalise the situation, reminding yourself that it will pass and that you won't always be sleep deprived.
She also suggests having a 15-30 minute power nap if possible to "take the edge off" your exhaustion.
Then, reach for your trusty mug.
Moira says having one or two coffees can give you an energy boost.
She recommends reaching for those cuppas before 2pm, so that your caffeine intake doesn't interfere with the following night's sleep.
If you're really feeling sleepy, she says getting up and moving around can help, as can a change of scenery.
And if you and your partner are suffering from lack of sleep, she advises speaking to a health professional and seeking further support.
Though this new study found a difference in how men and women's memories function after sleep deprivation, Moira says we can't use this research to determine which parent should get up overnight.
Instead, she believes that, when there's more than one parent, they should share the load while looking at factors, such as who has the most demanding day ahead, who needs more sleep and who copes better with sleep loss.
"Some people really do cope very well with five or six hours of sleep, and some people need nine or ten and it's a disaster if they don't get it."
So it looks like there are lots of ways we can help work out which parent should get up overnight – but that, despite this research, we shouldn't make that call based on gender.