When School Schedules Collide with Biological Clocks

School Administrator, March, 1994 by Timothy H. Monk

Benjamin Franklin's maxim, "Early to bed and early to rise, makes a man healthy, wealthy, and wise," may work well for the rest of us, but I question how appropriate it is for high school students.

Like millions of other children of his age group around the country, my son was required to adopt an early start to each day when he entered high school as a freshman last fall. A 6 a.m. wake-up time was mandated by the need to make it to the bus stop by 7 a.m. Since my job is to research the effects of disruptions of the human biological clock, my interest in the problem has been more than just paternal.

For many of my son's friends, the difference in daily habits, from the noon wakening and late bedtimes of summer vacation to the 6 a.m. waking of the high school day, represented a change in schedule equivalent in magnitude to that of a flight from New York to Berlin.

In the short term this meant that like millions of their peers, these kids were experiencing the adverse symptoms of "jet lag" for the first week or two of school. These symptoms include sleep disruptions at night, and irritability, inattentiveness, and drowsiness during the day--hardly a recipe for a productive start to the school year!

Harmful Impact

Sadly, though, biological changes to a young person's sleep and biological clock make these temporal adjustments even more difficult to accommodate, and are likely to make them last for much longer than the first few weeks after a vacation. As shown in a series of studies by Mary Carskadon, director of the Sleep Laboratory at Brown University, our high school students are at an age when they need lots of sleep, but also at an age when they make the transition from "morning lark" to "night owl."

In contrast to their younger years, preferred wake-up times get later and later, but run up against school bus schedules that require early wake-up times. Not surprisingly, Carskadon has documented extreme levels of sleepiness in these students, even leading to sleep during academic examinations!

The point also has been taken up by Richard Allen of the Sleep Disorder Center at Johns Hopkins University, who has shown that high school students typically show little accommodation of their sleep schedule to early start times, resulting in a buildup in sleep loss during the school week and low levels of alertness during the school day, particularly in high schools with very early start times.

At the other end of the school day is the situation where by 2:30 p.m. or earlier, the school day has ended for a group of children whose brains are only just beginning to wake up and become receptive.

In my own collaborative work with Simon Folkard of the British Medical Research Council on teen-agers' memory for material presented to them at different times of day, we found that a 3 p.m. presentation led to superior long-term retention than that of a 9 a.m. presentation. This single study from England in the 1970s was far from definitive, but it did suggest that some of the early work by educational psychologists in the 1910s and 1920s may have concentrated too much on computational skills such as mental arithmetic (which are, indeed, best done in the morning), rather than consolidation into long-term memory (which, like many physical skills, seems to be done best in the late afternoon). The early work also predated the invention of late-night television, of course!

Better Sense

One irony of the situation for many high school students is that when their biology was more suited to an early waketime, during elementary school years, school started several hours later, leading to unfilled time between wake-up time and the start of school, and to baby-sitting problems for working parents with long morning commutes. In contrast to older children, elementary school kids naturally wake early in the day, and are raring to go long before their 9:15 a.m. (or later) start time.

Would it not make more sense to switch the schedules around, having the elementary school students start earlier in the day and high school students later in the day? There would be no extra stress on bus schedules since the change represents just a switch. The parents of elementary school students would have fewer morning baby-sitting problems and, most importantly, our high school students would not be in the position of being half asleep for much of their school day, and at their most alert when school is over.

Of course, there are benefits and drawbacks to any change in schedule. At the moment, though, we are not even debating the issue but are content to do things the way they always have been done.

Let us now wake up to the new responsibilities and perhaps even wake up our high school students as a result.