rel="nofollow" href="#u977a62c2-0f0e-57a6-ba07-b6ec29daa5c9">chapter 1 we learned about some curious results on Denmark’s national standardized exams. Danish schoolchildren who take the tests in the afternoon score significantly worse than those who take the exams earlier in the day. To a school principal or education policy maker, the response seems obvious: Whatever it takes, move all the tests to the morning. However, the researchers also discovered another remedy, one with applications beyond schools and tests, that is remarkably easy to explain and implement.
When the Danish students had a twenty- to thirty-minute break “to eat, play, and chat” before a test, their scores did not decline. In fact, they increased. As the researchers note, “A break causes an improvement that is larger than the hourly deterioration.”12 That is, scores go down after noon. But scores go up by a higher amount after breaks.
Taking a test in the afternoon without a break produces scores that are equivalent to spending less time in school each year and having parents with lower incomes and less education. But taking the same test after a twenty- to thirty-minute break leads to scores that are equivalent to students spending three additional weeks in the classroom and having somewhat wealthier and better-educated parents. And the benefits were the greatest for the lowest-performing students.
Unfortunately, Danish schools, like many around the world, offer only two breaks each day. Worse, legions of school systems are cutting back on recess and other restorative pauses for students in the name of rigor and—get ready for the irony—higher test scores. But as Harvard’s Francesca Gino, one of the study’s authors, puts it, “If there were a break after every hour, test scores would actually improve over the course of the day.”13
Many younger students underperform during the trough, which risks both providing teachers with an inaccurate sense of their progress and prompting administrators to attribute to what and how students are learning something that is really an issue of when they’re taking a test. “We believe these results to have two important policy implications,” say the researchers who studied the Danish experience. “[F]irst, cognitive fatigue should be taken into consideration when deciding on the length of the school day and the frequency and duration of breaks. Our results show that longer school days can be justified, if they include an appropriate number of breaks. Second, school accountability systems should control for the influence of external factors on test scores . . . a more straightforward approach would be to plan tests as closely after breaks as possible.”14
Perhaps it makes sense that a cup of apple juice and a few minutes to run around works wonders for eight-year-olds solving arithmetic problems. But restorative breaks have a similar power for adults with weightier responsibilities.
In Israel, two judicial boards process about 40 percent of the country’s parole requests. At their helm are individual judges whose job is to hear prisoners’ cases one after another and make decisions about their fate. Should this prisoner be released because she’s served enough time on her sentence and shown sufficient signs of rehabilitation? Should that one, already granted parole, now be permitted to move about without his tracking device?
Judges aspire to be rational, deliberative, and wise, to mete out justice based on the facts and the law. But judges are also human beings subject to the same daily rhythms as the rest of us. Their black robes don’t shelter them from the trough. In 2011 three social scientists (two Israelis and one American) used data from these two parole boards to examine judicial decision-making. They found that, in general, judges were more likely to issue a favorable ruling— granting the prisoner parole or allowing him to remove an ankle monitor—in the morning than in the afternoon. (The study controlled for the type of prisoner, the severity of the offense, and other factors.) But the pattern of decision-making was more complicated, and more intriguing, than a simple a.m./p.m. divide.
The following chart shows what happened. Early in the day, judges ruled in favor of prisoners about 65 percent of the time. But as the morning wore on, that rate declined. And by late morning, their favorable rulings dropped to nearly zero. So a prisoner slotted for a 9 a.m. hearing was likely to get parole while one slotted for 11:45 a.m. had essentially no chance at all—regardless of the facts of the case. Put another way, since the default decision on boards is typically not to grant parole, judges deviated from the status quo during some hours and reinforced it during others.
But look what happens after the judges take a break. Immediately after that first break, for lunch, they become more forgiving— more willing to deviate from the default—only to sink into a more hard-line attitude after a few hours. But, as happened with the Danish schoolchildren, look what occurs when those judges then get a second break—a midafternoon restorative pause to drink some juice or play on the judicial jungle gym. They return to the same rate of favorable decisions they displayed first thing in the morning.
Ponder the consequences: If you happen to appear before a parole board just before a break rather than just after one, you’ll likely spend a few more years in jail—not because of the facts of the case but because of the time of day. The researchers say they cannot identify precisely what’s driving this phenomenon. It could be that eating restored judges’ glucose levels and replenished their mental reserves. It could be that a little time away from the bench lifted their mood. It could be that the judges were tired and that rest reduced their fatigue. (Another study of U.S. federal courts found that on the Mondays after the switch to Daylight Saving Time, when people on average lose roughly forty minutes of sleep, judges rendered prison sentences that were about 5 percent longer than the ones they handed down on typical Mondays.15)
Whatever the explanation, a factor that should have been extraneous to judicial decision-making and irrelevant to justice itself—whether and when a judge took a break—was critical in deciding whether someone would go free or remain behind bars. And the wider phenomenon—that breaks can often mitigate the trough—likely applies “in other important sequential decisions or judgments, such as legislative decisions . . . financial decisions, and university admissions decisions.”16
So if the trough is the poison and restorative breaks are the antidote, what should those breaks look like? There’s no single answer, but science offers five guiding principles.
1. Something beats nothing.
One problem with afternoons is that if we stick with a task too long, we lose sight of the goal we’re trying to achieve, a process known as “habituation.” Short breaks from a task can prevent habituation, help us maintain focus, and reactivate our commitment to a goal.17 And frequent short breaks are more effective than occasional ones.18 DeskTime, a company that makes productivity-tracking software, says that “what the most productive 10% of our users have in common is their ability to take effective breaks.” Specifically, after analyzing its own data, DeskTime claims to have discovered a golden ratio of work and rest. High performers, its research concludes, work for fifty-two minutes and then break for seventeen minutes. DeskTime never published the data in a peer-reviewed journal, so your mileage may vary. But the evidence is overwhelming that short breaks are effective—and deliver considerable bang for their limited buck. Even “micro-breaks” can be helpful.19
2. Moving beats stationary
Sitting, we’ve been told, is the new smoking—a clear and present danger to our health. But it also leaves us more susceptible to the dangers of the trough, which is why simply standing up and walking around for five minutes every hour during the workday can be potent. One study showed that hourly five-minute walking breaks boosted energy levels, sharpened focus, and “improved mood throughout the day and reduced feelings of fatigue in the late afternoon.” These “microbursts of activity,” as the researchers call them, were also more effective than
