If you’re having trouble falling asleep, maybe you can rest easy knowing that if you just had a sense of purpose in life, you’d already be dreaming. But probably not. In all likelihood, that anxiety-inducing thought is actually going to make it harder for you to get enough sleep. That’s not stopping some neurologists from recommending “purpose” as a solution to your insomnia.
That may sound ridiculous to you. Good! You’re appropriately skeptical. You may have recently seen some far-fetched headlines about drifting into dreamland more quickly once you find your purpose in life, and you may have even read some of the attached articles. So let’s talk about the actual study behind all this coverage.
These findings found their way into trending Google News headlines by way of Northwestern’s School of Medicine, where three neurologists decided to take a look at whether a sense of purpose correlated with better sleep quality. Their results were published in Sleep Science and Practice on Monday. The study involved a lot of statistical analysis, but it basically relies on two things: a survey that attempts to quantify whether a person has a purpose in life, and a survey that attempts to quantify sleep quality. Both rely on self-reporting, meaning that study subjects assessed themselves, and are therefore subject to bias. Do you always remember how many hours you’ve slept, and are you sure you’d be honest on a survey designed to quantify your sense of fulfillment? But hey, maybe everyone in this study accurately reported everything about themselves. There’s still the small issue that the researchers found almost nothing of statistical significance.
Yes, the team did find that people who reported having a sense of purpose also reported better sleep. And yes, technically they found that a year later, people who gained some sense of purpose also gained some sleep quality points. But they failed to find any effect two or three years out from the baseline study, which seems a little suspect. If achieving a sense of purpose makes you sleep better, surely that effect should last, no? Apparently not.
But there’s also another layer to this. If having a purpose in life made you a better sleeper, you’d expect that even within one group, those with more purpose would have higher sleep quality. In scientific terms, we’d call that accounting for variance. If you measure sleep quality and “sense of purpose” accounts for a large percentage of the variance in sleep quality between people, that’s a fairly good indicator that sense of purpose (or lack thereof) significantly impacts sleep.
So guess how much variance a sense of purpose accounted for in sleep quality in this study? 4.3 percent. To their credit, the authors note this in the final paragraph of their paper, where they discuss potential limitations of their findings. Also listed? The fact that most of the study group was highly educated and therefore likely had access to good health care and the information and resources required to make healthy choices. They probably had pretty high quality sleep to begin with. All those things are especially true of older Americans, as high educational level and socioeconomic status (which already go hand-in-hand) are highly predictive of healthy diets and good exercise regimens, which tend to help you sleep better. This is where I should mention that the study focused only on older Americans, by the way, so even if the results were iron-clad and universally applicable, you’d still only be able to say the findings held true for an older cohort. You young rebels can carry on without a cause.
But when you look at all of the study’s limitations, it’s clear that having a sense of purpose in life isn’t a driving factor in getting you to sleep—it’s more of a marker. If you’re the sort of person who has had the time and resources to really investigate what’s important to you and what would make you happy in the grand scheme of things, you’re probably also a person who is wealthier and healthier.
If you’re struggling financially—working long hours, or even multiple jobs—you’re probably not spending a lot of time considering what your deeper purpose is. You’re also less likely to sleep well. The same goes for dealing with family troubles, or facing daily racism, or trying to climb a social ladder that’s stacked against you. Heck, if you’re too poor to afford a comfortable bed or proper heating and air conditioning, you probably aren’t getting great sleep, either. Really, the results of the study should be framed as “people who sleep better are more likely to have a sense of purpose in life.” Better yet, “people who sleep better generally live easier lives.”
Even if all of the problems with this study were moot, it’s not like this would be particularly helpful advice. How exactly do you find your purpose in life? Are you supposed to do that on top of tackling the rest of your arguably-much-more-pressing concerns? And if you manage to find your bliss and your bedroom is too hot, you’re still going to toss and turn. More power to you if you want to find your purpose in life—it will almost certainly help you to be a happier person. Just don’t expect it to make you sleep better.
