Why do classes start so early

Thus, even though these students had the first year of their 2-year course with the 10 a. The whole pattern for the combined results of the field experiment and the natural experiment is clear in Figure 2. In Year 0, student success in the target school was actually 5 percentage points below what would have been expected in light of the students' prior performance FFT. Then the field experiment began. The introduction of the 10 a. There was a further small rise to a value added of 12 percentage points in Year 2 for the cohort which had experienced the 10 a.

The field experiment then ended. The natural experiment then reverted the start time to , so students in the Year 3 cohort had the first year of their course with the 10 a. Value added was still positive for this cohort, but had fallen by 4 percentage points compared to the previous cohort which had 2 years of 10 a. Based on this study, moving school start times later so that they are better aligned with adolescent sleep and chronotype patterns is practical and beneficial.

Following a change to a a. When the school start time was returned to a. These findings suggest that the general policy recommendation to start high schools no earlier than a. As the a. The absence due to illness rate data are consistent with a direct benefit of later school starting times on student health. The differentiation in recording absence and absence due to illness in England offers a more precise measure of illness and a large national data set.

Following initiation of the a. With the return of an a. Academic performance of students aged 14—16 also improved with a a. There is no reason to believe that these outcomes reflected motivation changes. The pupils were studying for their final national exams, which determine their eligibility for continued study and ultimately college or university, or their competitiveness in the jobs market.

These were not study-related tests but the real, once-in-lifetime exams that have a major influence on the children's futures and thus would be equally motivated. While there are several possible explanations for the poor performance of students in similar low socioeconomic status areas, the possible impact of sleep restriction linked to early school starts has rarely been considered. One of the objections raised to changing school start times is that the change is impractical and cannot overcome other barriers, such as bus timetables or sports program scheduling.

While the English legal framework makes changing to much later start times a formal process any school can undertake and therefore more practical than in some other countries , moving all of this school's schedules later produced no practical difficulties. By choosing a 10 a.

Even later start times might address this issue, but 10 a. The national US recommendation that middle and high schools should start after a.

A recent study of university students aged 18—19 found that later starting times after 11 a. The study also found that using a fixed time for all students would disadvantage one or more chronotypes, and evening chronotypes in particular if starts were early Kelley et al. Thus, even with the benefits accrued using a 10 a. The limitations in this study include small sample sizes in some measures, a focus mainly on illness, and an inability to measure students' sleep duration.

Although other studies have shown sleep improvements following less substantial interventions, some have tracked sleep improvements over 4 years and found that improvements persist Borlase et al. The English location and measures of academic performance are difficult to contextualize with previous research using U.

The nationally available data on illness on a school-by-school basis, focus on students in mid-adolescence and the starting time of a. A larger, more detailed study is needed of school starts after a. There is preliminary evidence that such changes can have benefits, particularly for older students Carrell et al. The school-level improvements in performance in this study, if more widely replicated, should be examined from economic and educational perspectives.

For example, expenditure to reduce the English attainment gap between rich and poor students reached more than one billion pounds between and , and yet had relatively little impact compared to the gains made following the 10 a. The change to smaller schools in key U. Other educational policy changes including creating new kinds of school such as Charter, Academy, and Science, Technology, Engineering and Math STEM schools, increasing the duration of school times, curriculum and test changes, or No Child Left Behind also have very high expenditure but minimal impact and little scientific rigor in evaluating their effects.

In contrast, changing to later start times is a very cost-effective intervention to raise educational standards with substantial scientific backing Jacob and Rockoff, ; Snow, ; Hafner et al.

The broader impact of later starts on specific aspects of adolescent health, such as sleep duration and quality, mental health, and social development were not assessed, although other studies have shown potential impacts de Souza and Hidalgo, ; Meltzer et al. Additional research into much later starts should measure both actual sleep patterns and optimal performance times for individual students.

The most important area for further research may be the impact of later starts on areas of social behavior development and mental health. Sleep deprivation is also associated with adolescents being less perceptive readers of human emotions van der Helm et al.

These interrelated factors of significant sleep deprivation, genetic predisposition, the high prevalence of the onset of mental illness during adolescence for a range of disorders Schmitt et al. Using a research-based approach to determine a school starting time for 13 to year-old students led to the implementation of a 10 a. This later starting time had a substantial benefit for rates of illness and academic performance.

A research-based approach to school starting times is clearly replicable in different contexts, cultures, and countries. More importantly, a post a. Application of sleep research in this way demonstrates the powerful impact on society and individuals of making evidence-based policy changes. Parents and students were consulted during the change as legally required. SL has had a number of commercial interests in the last 12 months — None are directly related to the research or topic reported in this paper but, in the interests of full disclosure, are outlined below.

Lux Software LLC; royalties from Oxford University Press; and has served as a paid expert in legal proceedings related to light, sleep and health.

The other authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

The authors would like to thank Professors David Reynolds, Russell Foster, and Daniel Muijs for their contribution to the thinking behind changing the start time based on sleep research, and David Reynolds contributed in its implementation as Chair of The Innovation Trust. Available online at: www. American Medical Association News Release. American Academy of Pediatrics Adolescent Sleep Working Group: school start times for adolescents.

Pediatrics , — CrossRef Full Text. Basch, C. Prevalence of sleep duration on an average school night among 4 nationally representative successive samples of American high school students, — Chronic Dis.

Blakemore, S. Is adolescence a sensitive period for sociocultural processing?. Borlase, B. Effects of school start times and technology use on teenagers' sleep: — Sleep Biol. Rhythms 11, 46— Carrell, S. A's from Zzzz's? The causal effect of school start time on academic achievement of adolescents. Carskadon, M. Sleep's effects on cognition and learning in adolescence.

Brain Res. Churches, R. London: Crown House Publishing. Google Scholar. Curcio, G. Sleep loss, learning capacity and academic performance. Sleep Med. Danner, F. Adolescent sleep, school start times, and teen motor vehicle crashes. PubMed Abstract Google Scholar. Midpoint of sleep on school days is associated with depression among adolescents.

Department for Education Edwards, F. Early to rise? The effect of daily start times on academic performance. Evans, M. Identifying the best times for cognitive functioning using new methods: matching university times to undergraduate chronotypes.

Foster, R. Sleep and circadian rhythm disruption in social jetlag and mental illness. Which connects to the third common category of opposition to changing the school day: concerns about funding a longer day. Increasing the amount of time that schools operate each day, as Brown favors, would cost money.

She cites this as another reason that changing the school day is difficult. Still, she says, there are ways for schools to adapt. As she outlined in a report , there are a few ways that schools could apply for federal funding to extend the school day under the Every Student Succeeds Act of Also, she says schools could have outside enrichment programs step in for a period of the day.

At any rate, many parents already are paying for the fact that the school day ends before the workday, in the form of childcare or extracurriculars. There is probably no such thing as a school-day schedule that satisfies every constituency. Make start times later, and people involved in sports and other extracurriculars complain, and transportation costs go up.

Keep school days the usual length, and working parents are in a jam. Make school days longer, and both students and teachers might dread the added time. But still, it seems an amended school-day schedule could make a lot of these people collectively less unhappy than they are now. Some of these were private after-school programs run by churches or community centers and some were public libraries; playgrounds staffed with supervisors to watch over children.

It would just take creativity, some reallocating of money, and most of all a collective resistance of inertia. Skip to content Site Navigation The Atlantic. As a final check on the accuracy of my results, I perform analyses that compare the achievement of individual students to their own achievement in a different year in which the middle school they attended started at a different time.

For example, this method would compare the scores of 7th graders at a school with a start time in to the scores of the same students as 8th graders in , when the school had a start time of As this suggests, this method can only be used for the roughly 28 percent of students in my sample whose middle school changed its start time while they were enrolled. My first method compares students with similar characteristics who attend schools that are similar except for having different start times.

The results indicate that a one-hour delay in start time increases standardized test scores on both math and reading tests by roughly 3 percentile points. As noted above, however, these results could be biased by unmeasured differences between early- and late-starting schools or the students who attend them. Using my second method, which mitigates this bias by following the same schools over time as they change their start times, I find a 2.

My second method controls for all school-level characteristics that do not change over time. However, a remaining concern is that the student composition of schools may change. For example, high-achieving students in a school that changed to an earlier start time might transfer to private schools.

To address this issue, I estimate the impact of later start times using only data from students who experience a change in start time while remaining in the same school.

Among these students, the effect of a one-hour later start time is 1. These estimated effects of changes in start times are large enough to be substantively important. The benefits of a later start time in middle school appear to persist through at least the 10th grade.

The comprehensive exam measures growth in reading and math since the end of grade 8 and is similar in format to the end-of-grade tests taken in grades 3—8. Controlling for the start time of their high school, I find that students whose middle school started one hour later when they were in 8th grade continue to score 2 percentile points higher in both math and reading when tested in grade I also looked separately at the effect of later start times for lower-scoring and higher-scoring students.

The results indicate that the effect of a later start time in both math and reading is more than twice as large for students in the bottom third of the test-score distribution than for students in the top third. The larger effect of start times on low-scoring students suggests that delaying school start times may be an especially relevant policy change for school districts trying to meet minimum competency requirements such as those mandated in the No Child Left Behind Act.

The typical explanation for why later start times might increase academic achievement is that by starting school later, students will get more sleep.

As students enter adolescence, hormonal changes make it difficult for them to compensate for early school start times by going to bed earlier. Because students enter adolescence during their middle-school years, examining the effect of start times as students age allows me to test this theory. If the adolescent hormone explanation is true, the effect of school start times should be larger for older students, who are more likely to have begun puberty.

I therefore separate the students in my sample by years of age and estimate the effect of start time on test scores separately for each group. In both math and reading, the start-time effect is roughly the same for students age 11 and 12, but increases for those age 13 and is largest for students age 14 see Figure 2.

This pattern is consistent with the adolescent hormone theory. To further investigate how the effect of later start times varies with age, I estimate the effect of start times on upper elementary students grades 3—5.

If adolescent hormones are the mechanism through which start times affect academic performance, preadolescent elementary students should not be affected by early start times. I find that start times in fact had no effect on elementary students. However, elementary schools start much later than middle schools more than half of elementary schools begin at , and almost all of the rest begin at As a result, it is not clear if there is no effect because start times are not a factor in the academic performance of prepubescent students, or because the schools start much later and only very early start times affect performance.

Of course, increased sleep is not the only possible reason later-starting middle-school students have higher test scores. Students in early-starting schools could be more likely to skip breakfast. Because they also get out of school earlier, they could spend more or less time playing sports, watching television, or doing homework. They could be more likely to be absent, tardy, or have behavioral problems in school.

Other explanations are possible as well. While my data do not allow me to explore all possible mechanisms, I am able to test several of them.

I find that students who start school one hour later watch 12 fewer minutes of television per day and spend 9 minutes more on homework per week, perhaps because students who start school later spend less time at home alone. Students who start school earlier come home from school earlier and may, as a result, spend more time at home alone and less time at home with their parents. If students watch television when they are home alone and do their homework when their parents are home, this behavior could explain why students who start school later have higher test scores.

In other words, it may be that it is not so much early start times that matter but rather early end times.