The Big Sleep

Until we get the job done at night, we have no hope of winning the day

Academic outcomes for American students have been declining for more than a decade.

It’s been difficult to say why. When these trends first arose, economists suspected they were caused by school funding cuts during the Great Recession. But even when budgets rebounded in the 2010s and increased during COVID, achievement kept dropping.

Another possibility is the demise of federal accountability once No Child Left Behind was replaced in 2015. Left to their own devices, states lost focus on what schools are supposed to do.

And then there is the rise of screen time. Kids have been increasingly distracted by algorithmic online content, driven to misery and isolation by countless hours spent staring at their devices - including while they are at school.

I’m persuaded that each of these theories has some validity. But - at least for me - they don’t fully explain the specific shape of a long-term deterioration that is:

• Broad: Almost the entire country is doing worse. Only Louisiana has higher fourth grade NAEP reading scores than it did in 2019. Only Alabama has improved in fourth grade math. Every other state is flat or down. This is a mess from sea to shining sea.

• Much worse for strugglers: Top scoring students - those at the 75th and 90th percentiles of the distribution - are doing as well as ever. In some states, they have improved. But today’s students at the 25th and 10th percentiles are scoring far lower than their peers a decade ago. The bottom has fallen out.

• Closely tied to family demographics: Students whose parents graduated college are scoring at very similar levels to peers from 25 years ago. Students whose parents did not graduate college are not doing nearly so well today as did earlier cohorts. That’s exactly the opposite of what our schools are supposed to be accomplishing, in terms of maximizing opportunity for kids of all backgrounds. The graph below shows scores for 8th grade NAEP math since 2000. From 2000 to 2013, scores generally improved for both groups and the gap was around 20 points, or two years’ learning. By 2024, the gap was 26 points - largely due to children of non-grads dropping so much more after the onset of the pandemic.

What would cause achievement to move in this particular way? I’ve spent more time than I care to admit thinking about it.

There’s a culprit that fits our pattern quite well. It has moved significantly in recent years. We have incontestable evidence that it affects development and learning. Shifts have been most evident with less privileged students, contributing to everything from absenteeism to classroom disruption to grade inflation. And so far as I can tell, we aren’t doing diddly-squat about it.

I’m talking about sleep. Or more specifically, lack of sleep.

How important is sleep?

Answer: super important. Beginning with toddlers aged 1-3, researchers find that sufficient sleep is associated with better language acquisition, stronger memory and executive function, improved behavior regulation, and higher performance on literacy and numeracy tasks in pre-K and kindergarten. On the flip side, little ones who don’t sleep enough tend to exhibit shorter attention spans and less cognitive flexibility.

Critically, early sleep habits often persist into later childhood, influencing long-term academic trajectories.

For decades, researchers have established links between sleep and socioeconomic (SES) factors. Mothers who graduated college are more aware of how much sleep kids require at each age. Their children sleep longer than the children of less educated mothers.¹ Among racial groups, Black youth aged 6-19 average 30 minutes less sleep per night than their White peers.

It’s almost like sleep is a privilege.

Here’s something that surprised me: Even though children from lower SES and marginalized communities are frequently not sleeping as much as guidelines suggest, they are less likely to self-report inadequate sleep. Put a pin in that. We’ll come back to it.

Sleep patterns have changed

Adolescent sleep has been moving in the wrong direction for decades. Around 2013, however, deprivation started growing quickly. Eight hours per night is considered sufficient for teenagers.² The graph below shows the share of kids reporting that they don’t get that much.

According to another national data set from 2021, about 40 percent of boys and nearly 50 percent of girls got only seven hours per night - or less. A decade earlier, both figures were around 33 percent. Chew on that for a moment. There are now several million more drowsy zombie children wandering our high school hallways.

As

Jonathan Haidt

and Jean Twenge have shown, the primary driver of the post-2013 surge is nocturnal screen time. Heavy smartphone users are the most likely to have short sleep duration.

If you haven’t been raising or teaching teenagers lately, you may not realize how batty things have become. By 2010, over 80 percent of teens with phones reported that they slept with their device on or near their beds. Those who texted were substantially more likely to keep their phones nearby.

By 2014, 80 percent of boys and 90 percent of girls were using their phones in the hour before bed - just when they should have been winding down from the blue light adrenaline rush of being online and producing melatonin to sleep. Those who continued engaging with their devices overnight - perhaps because of constant notifications - woke more often, for longer periods of time, and got less total sleep.

Even among younger adolescents, it’s bad. A study earlier this year found that 1 in 4 kids aged 11-13 now sleep with their phone in their hand or in their bed. Not nearby. Attached.

In short, smartphones have conquered the wee hours, with sleep as the casualty. What could go wrong?

Sleep deficits are hurting schools

In the wake of COVID, educators have struggled with every manner of challenge. The students who don’t sleep - the ones who stay up late into the night on their devices and use them intermittently until dawn - are likely to be the source of those challenges.

• Chronic absenteeism. I wrote a three-part series in 2023 about kids missing school. Talked to dozens of people, read all sorts of papers. None of them cited inadequate sleep as a primary driver. In hindsight, I feel embarrassed that I didn’t do more legwork. A large-scale Norwegian study had already found in 2015 that adolescents with short sleep duration had four times the likelihood of school non-attendance compared to their well-rested peers. More recently, a California district reported in 2024 that low sleep was second only to illness as a cause of missing school among their students. At a recent American Enterprise Institute event, University of California, Davis professor Kevin Gee shared data taken from hundreds of thousands of student surveys in Rhode Island. He found that - again - lack of sleep is the leading cause of absenteeism after illness.

• Decreased learning. A 2023 CDC study of student wellness during the pandemic found that students reporting less than seven hours of sleep per night - and to reiterate, this is approximately 40 percent of boys and half of girls - also had more trouble with academics.³

• Fighting. A 2019 study from Portugal found that low sleep was a significant predictor of participation in physical fights among 17-year-olds even after controlling for parental education levels. No wonder principals were dizzied by a brawl uptick in 2022 and 2023.

• Grade inflation. With kids missing so much school and getting less sleep, schools have largely responded by decreasing rigor. Less homework, unlimited opportunities to retake tests, easy avenues to make up missed assignments after absences. I was part of a research project last year that found grades now remain high even when students have lower test scores and miss more school.

When discussing our failed COVID recovery, we often describe a widespread mental health epidemic driven by the toxicity of social media, too little time socializing in the real world with friends, and residual trauma from family members lost during the pandemic.

All true. But as we get further from 2020 and our problems linger, it seems like there’s more to the story. In addition to these other factors, COVID exacerbated challenges with sleep by increasing screen time particularly in ways that interfere with healthy nighttime and morning routines. It’s not just how much screen time. It’s when.

We have no strategy for addressing our sleep problems

I’m far from the first person to suggest that sleep for children and adolescents is an issue.⁴ It’s a known thing. But I am concerned that we aren’t making a strong connection between sleep and school - nor are we taking initiative to solve the problem. Let’s focus on absenteeism as an example:

• I downloaded and searched the strategic plans for the 10 largest districts. Not one of them mentions sleep, even though all of these districts have problems with absenteeism.⁵

• The US Department of Education’s guide to combatting absenteeism does not include the word “sleep.”

• Attendance Works, a leading non-profit on absenteeism that has done so much to advance our understanding of the problem, does not emphasize sleep as a direct strategy. Their most aligned recommendation is moving school start times later… which strikes me as accommodating our nighttime sleep deficits rather than fixing them.

To recap, we have an epidemic of chronic absenteeism. Students are telling us that lack of sleep is the second-biggest cause. I’m just suggesting that we can find room to address it as one part of a broader strategy.

Meanwhile, teachers get the shaft. Districts issue devices to kids beginning in kindergarten. Most of these devices have zero time limitations. They don’t shut off at a certain time each night. Parents who require their kids to store their phones in the kitchen at night often learn belatedly that the iPad their child uses for “homework” is repurposed into a late-night texting device via Google Docs.

Then, when kids show up to class red-eyed and unable to focus, teachers bear the brunt. In addition to supporting a broad range of academic needs, they are now managing a range of alertness. They can’t assign homework. Kids are too tired and distracted to do it. Some schools give up and decree that homework doesn’t count toward grades. Teachers are navigating student conflicts fueled by frayed nerves and fatigue. And then, at the end of the school year, everyone wants to know why the kids aren’t learning. We can’t be surprised that today’s educators don’t recommend their profession to others.

Rather than trying to get students proper rest, schools have tended to address pandemic issues by hiring more staff to support mental health. There are two problems here. First, are these folks doing anything to help kids get more sleep, which seems like a top mental health need? If so, why isn’t that reflected in the districts’ plans? Second, how are we going to afford all these new hires when we hit the funding cliff that’s approaching?

Indirect approaches aren’t going to work. Sleep needs to be named and sustained as a priority. Districts can:

• Communicate with parents beginning in pre-K about how much sleep children need and how to help them get it, including bedtime strategies, getting off and storing devices, reading stories aloud together, limiting wake-ups, and establishing morning routines. As I mentioned above, research has shown for years that some families have less awareness about proper sleep duration. Can we not support them by fixing that? Check out Mansfield, Ohio.

• Disable school-issued student devices at a reasonable hour. This policy would send a powerful signal about the importance of sleep. Yes, you are going to get parents who swear their third grader needs the device to complete her math homework at 10pm. No, that’s not a real thing. Lights out.

• Teach parents to use phone monitoring software. Wirecutter’s top recommended apps for iPhones and Android devices are free. They can shut off devices at bedtime, limit access to social media, and block installation of new apps without permission. Do districts know how many families use the apps? Do school-based technology staffers offer support? The answer to both questions should be yes.

• Start sweating tardies and absences. Offer a blend of support for getting to school on-time and reasonable, proportional consequences for missed instruction. I’m talking about reflecting attendance in eligibility for honors, field trips, extracurriculars, and credit accumulation, not prosecuting parents. Give families some backup in getting their kids to bed on-time.

Our education depression will end when young people are healthy and engaged. Would any step be more powerful than addressing sleep? It’s critical. It doesn’t cost much money. It will boost happiness for kids, the adults who teach them, and their parents.

But will we take action? Or continue to watch it get worse?

1. Researchers did not find that having a more educated father influences sleep patterns - perhaps indicating who is doing the heavy lifting when it comes to setting household routines. I apologize on behalf of all dads. In my own house, since our kids were infants, my wife has run a bedtime operation so organized and purposeful, it makes a papal conclave look like a bounce house full of bees. Our kids slept. I am so grateful.

2. Recommended hours of sleep for each age group can be found here.

3. Ethan Hutt from University of North Carolina recently calculated that “chronic absenteeism accounts for about 7.5% of overall pandemic learning loss and about 9.2% for Black and low-income students.” The finding was characterized as “modest” but it strikes me as meaningful, especially since increased absenteeism has additional ripple effects like slowing the pace at which teachers cover material that also hold the potential to depress learning.

4. For further reading, Mary Carskadon has been publishing on sleep for decades.

Emily Oster

is wonderful at translating academic findings for the rest of us.

Michael Petrilli

has written compellingly about the ways smartphones are intruding on teenage sleep, to the detriment of learning.

5. It’s possible I missed something. Let me know if one of the big district strategic plans includes a focus on ensuring students get adequate nightly sleep and I can update.