But what does that mean for all those young people who have to perform in school during the early hours of the day? Note that in some regions of Europe, especially in Germany, schools start at seven o’clock in the morning—which means that some pupils have to get up at 5 A.M. or earlier in order to be in class on time.
13
What a Waste of Time!
Jacob needed a smoke and persuaded Felix to leave campus with him during the first morning break. He was in a really foul mood. He had slept far too little, his parents were on his back about his current performance in school, and now that thing in class again. His mother had talked to the teachers of his worst subjects. As a reaction—probably well meant by the teachers—they suddenly generated frequent opportunities for him to get higher oral grades to compensate for the bad ones he was getting in most of the written exams.
It had been the third time this week that Jacob had suddenly been confronted with a teacher’s anticipating and friendly face radiating something like: now Jacob, you can surely answer this extremely easy question. This time it was their math teacher, Mr. Blossop. The trouble was that he had no clue what the extremely easy question might have been. “What is this, Felix?” Jacob almost shouted at his friend after lighting up, “I sit next to you in class, I listen, and then suddenly, out of the blue, he’s in my face, and I don’t even remember what he was talking about. It’s like I had a complete blackout. Maybe Blossop was trying to help, but I just didn’t hear the question.” Jacob looked at Felix with desperation. “What did he ask me?”
“It was really simple,” answered Felix. “All he wanted to know was what the first derivative of a function tells you about the qualities of the original function.”
“That would be the slopes at every point of the original function,” answered Jacob.
“Exactly, so why didn’t you say so? You just sat there staring at him with a completely blank face as if he had asked you to prove it mathematically for all possible conditions.”
“Because I hadn’t even heard the stupid question! I already told you that! Are you having a blackout now?”
“I heard you, but Mr. Blossop doesn’t know that, and this isn’t the first time you’ve drawn a complete blank this week.”
Jacob took a last draw of his cigarette and chucked the butt into the bushes, and the two of them headed back to school. “It’s so unfair. Hilda just sits there in the first row, fresh as a daisy every morning, listening to whatever Blossop says with her big blue eyes wide open—catching every word of it. I bet she never has blackouts!” He looked at Felix, soliciting some support. “The first couple hours in school are a complete waste of time!”
Felix’s answer came as a surprise: “I’m sure that’s what some teachers think, too, when they have to deal with students like you.” Jacob wasn’t offended; he knew Felix far too well for that. First, Felix was much more alert than Jacob in the morning, and then he had this tendency to always see the other side.
Jacob thought that he was much better at math than Hilda but was never able to prove it. Why did they have to take all their tests first thing in the morning? He would have performed so much better at some later time of the day. Over the past few months, when he had realized that his performance in school was on the edge, he had really tried hard to go to sleep earlier on school nights. He had said “no” to every party invitation—even on weekends. But nothing helped—he just couldn’t get more sleep on schooldays. He caught up on schoolwork during the late evening, sometimes until the small hours of the morning. It didn’t help to go to bed earlier than 1 A.M., because he just couldn’t fall asleep.
While they walked through the school’s big hall toward the physics classrooms, Jacob noticed Ann, who lived on the same street as he did. Although she was quite a bit younger, he had thought about asking her out. When she turned around, Jacob read the slogan on the back of her tee shirt and smiled for the first time that morning.
A couple of years ago, I was invited to attend a hearing in the parliament of Saxony in Dresden. The opposition party had organized a debate on moving the beginning of school to a later time. In my short lecture, I gave an introduction into the nature and the mechanism of biological clocks and about their genetic background. At the end of my presentation, I described our findings on the peak of lateness in teenagers. Immediately after the chair of the hearing had opened the discussion, several schoolteachers—also members of the hearing panel—raised their hands. One of them, a physics teacher, seemed quite agitated and declared with strong conviction: “My students are fully awake at seven in the morning.” I asked him what age group he taught, and he answered: seventeen to eighteen. I then asked this confident physics teacher what evidence he had for his statement, and he declared with no less conviction, “I can see that—it’s perfectly obvious!”
It is quite remarkable how firmly belief and conviction stand in the way of reasoning. This was not a teacher of religion but of physics, who should understand the rules of science. What grade would he have given Jacob, for example, if he had answered the question “Is there evidence that the sun turns around the earth?” with a simple “Yes, there is—we can see it—it’s perfectly obvious!” But ever since Galileo’s time, scientists have agreed that only facts count in a scientific argument. After statements like these, my long-term collaborator, Martha Merrow, would frequently exclaim, “Show me the data!”
The next contribution to the discussion came from another teacher who was also the principal of a large school in a rural part of Saxony. He described in great detail the bussing system in his region and made it quite clear that the issue of biological clocks in youngsters was completely negligible. Both schoolchildren and workers had to be transported by the same bus company, and those buses had to be available for the workers at a certain time. Consequently there was no way to change the time of day when children could be bussed to school! That’s it; very simple; end of discussion!
As you can see, the level of this discussion was frighteningly low and shallow. I have had conversations of similar quality with many other teachers and politicians throughout Europe. One of them was a remarkable exchange with Bavarian politicians, carried out with the help of a large Munich tabloid. The tabloid had picked up on our findings regarding the biological lateness of adolescents and wrote a provocative piece advocating later school times. The next day’s issue of that newspaper contained an article under the headline “Sleep researchers caught sleeping.” The content of the article was an interview with the spokesperson for the Bavarian Ministry of Education, who gave a very entertaining, seemingly logical counterargument proving the ignorance of clock and sleep researchers. Hadn’t it been those very scientists who had found the infamous lunchtime dip? If school times were delayed—as those researchers obviously demanded—wouldn’t the poor children then have to be taught during this time of tiredness and short attention span? How could these researchers be so shortsighted?
When someone brought an issue of that paper into the lab the next day, I immediately called the ministry and got hold of the spokesperson who had been interviewed for the article. I told her that I was extremely interested in the sources that prompted her to make these statements because we certainly must have overlooked an important paper, and we wanted to amend that oversight immediately. She was very friendly—as spokespeople probably should be, given their job description—and promised to send me the sources the next day. Let me specify the source that I waited for: a study showing that delaying school start times led students to be more tired at the end of a full morning’s teaching than if school had started earlier. In many more words I was quoting Martha: “Show me the data!” The promised sources were never produced, not even after several reminders.
I could fill this book with similar debates, which would be highly repetitive and boring, but I will recount a last example to round things up. A German newspaper once invited me to participate in a debate with the president of the German Teachers Association. In n
o more than 200 words—without knowing what the other would write—we were to make our statements for or against the introduction of later school times. The president summarized his counterargument in four points. First, he asserted that the daily peaks of performance are individually too different to warrant later school times, so that times between 8 A.M. to 1 P.M. constitute an excellent compromise for all chronotypes. The president added that the reason for students not being awake in the morning was only—if we were really honest!—because they regularly went to bed too late. Second, he was convinced that the majority of parents wanted schools to start at 8:00 because they themselves had to go off to work. Third, he described at length the bussing difficulties, as had his colleague in Dresden. Finally, after talking to students, he had become convinced that 90 percent of them favored being in school by 8 A.M. because they wanted to be home by 1 P.M.
An astonishing set of statements! Again the arguments are predominantly based on conviction (a word my adversary used frequently throughout his text) and belief rather than on facts. Some of his arguments merely show a lack of information. It is delectable that the first statement acknowledges the existence of individual differences in chronotype. The argument overlooks, however, that the distribution of chronotypes within a given age group moves to later times during adolescence—everyone becomes considerably later, regardless of individuality. It also neglects the fact that the entire distribution—including young and old—is already so late in our present day and age that well over 60 percent of the population would have difficulty fully concentrating during the first hours of school. The statement about the traditional school times being an excellent compromise is, therefore, not supported by data. The first statement ends with the disco hypothesis. The tragic thing is that every one of the sub-statements is true: adolescents aren’t fit in the morning—because they haven’t slept enough—because they went to bed too late. All true—but why?
The president’s second statement about parents being afraid of losing control over their children in the morning reflects a common misunderstanding. The discussion about later school times predominantly concerns adolescents. Why shouldn’t high school students leave the house after their parents? His third statement about the buses obviously speaks to a difficult logistical problem—why else would it pop up so often when school times are discussed? Education is a nation’s investment in its future. If there is a chance to increase the quality of such an important investment, then logistical problems, such as bussing, have to be solved on the long view—even if this is difficult. They should not be used as a valid argument against improving the investment in our next generation. Finally, the president presented no evidence for his fourth statement. With how many students had he spoken, and what were the questions? Might the students have answered differently if the question had been asked by a classmate? In addition, although I have witnessed innumerable changes in school policies, none of them would have been stopped just because students didn’t want it. So after hearing a lot of beliefs and convictions, let’s try and find some facts.
The most important fact has already been presented: the adolescent clock delays by several hours, reaching a peak in lateness at around twenty. The facts supporting a biological rather than a social reason for this delay are overwhelming. Mary Carskadon was the first scientist who recognized the biological rather than social basis for lateness in teenagers.1 Her first papers showing this tendency were published in the early 1990s. Since then, many studies have monitored what happens to students when school times are changed. The results of these studies are extraordinarily clear. When Carskadon brings students into a sleep laboratory instead of sending them to school at their normal early time, she finds that many students show the signs of a major sleep disorder—narcolepsy.2 When given the chance, they fall asleep at once and immediately enter a sleep stage called REM.3 Normally this stage is more typical of the end of sleep than of its onset, showing that these students are physiologically still asleep, despite having gotten up in the morning. In their immediate entry into REM sleep, these students resemble patients suffering from narcolepsy. If people are so tired that they show a behavior normally found only in narcoleptics, they also tend to have increased episodes of micro-sleep. As a result of these episodes, people experience a short loss of consciousness, similar to what Jacob experienced. Often neither the affected individual nor people witnessing such events are aware of these micro blackouts. As a matter of fact, many car accidents that happen at night on empty roads are a consequence of micro-sleep episodes. The lucky drivers who survive such accidents have no recollection how they ran off the road.
Teenagers need around eight to ten hours of sleep but get much less during their workweek. A recent study found that when the starting time of high school is delayed by an hour, the percentage of students who get at least eight hours of sleep per night jumps from 35.7 percent to 50 percent.4 The adolescent students’ attendance rate, their performance, their motivation, even their eating habits all improve significantly if school times are delayed.
The president’s claim that the traditional school times are a good compromise for all students isn’t only factually incorrect. The traditional school times blatantly discriminate against late chronotypes, who make up the majority among teenagers. This isn’t a good compromise for people who are not awake at seven or eight. Early types, however, could still perform just as well if schools started later. A German study assessed the chronotypes of university students and compared them with their grades on their final high school exams.5 The resulting correlation is frightening. The later the chronotype of a student, the worse the grades.
The resistance of teachers and politicians to start schools later for teenagers is even greater in those systems where school is predominantly restricted to the morning, and teachers are accustomed to spending the afternoon at home correcting homework and preparing lessons. Delaying school times would certainly mean an adjustment to their schedules. As adults, most teachers have shifted to an earlier chronotype. There even may be a tendency in the teaching profession to self-select for early chronotypes. Despite these barriers, the number of schools trying out other timetables for adolescent students is rapidly increasing in several countries, from Switzerland to the United States.
A recent Danish project has eliminated timetables entirely and left the decision about when to arrive at school to the students.6 One of the teachers of this school in Copenhagen recently pointed out in a television interview that schools should be regarded as service centers, and so they are required to offer the best possible service to their customers, meaning the optimal environment for achieving the best education possible. Allowing students to sleep and work at their optimal times should definitely be part of this service. Scientists are monitoring this school project, and I am eager to see the first results. But how far should we go in letting adolescents choose their wake and sleep times? Wouldn’t that lead into a day-night inversion, so that teachers would have to start their classes at eight in the evening? To answer this question, we will explore in more detail the mechanisms (called entrainment) of how the clock synchronizes to the twenty-four-hour day.
14
Days on Other Planets
It is the year 2210. The world never really recovered from the big economic depression two hundred years ago. Concern for the environment and nature goes down the drain in times of financial hardship. As a consequence, many regions of our globe have become unlivable for most plants, animals, and humans. The area usable for human settlements has been reduced to a tenth of what was available around the turn of the millennium and continues to decrease rapidly. Places to live are not the main problem—humans have retreated to higher regions, shielded from the rising ocean levels, or live in fantastic underwater worlds. Area to produce the necessary resources to support Earth’s remaining human population is vanishing, however: agricultural land hardly exists and the formerly food-rich oceans are overfished and overpolluted.
At
the headquarters of the World Agency for Space Settlements, WASPS, which has recently been moved to the summit of Mont Blanc, a committee of scientists meets to discuss the possibilities of evacuating their troubled planet. The exploration of other planets in our Solar System has been quite successful, and human settlements have been established on most of them. Although environmental issues have been neglected, research, technology, and development—RTD—has reigned supreme. The technical problems involved in creating an earthlike environment have been solved on most planets. Scientists know that it is essential—in the long run—to create settlements that are somewhat in contact with whatever one would call nature on these ersatz planets. They decided to build the settlements under huge, transparent domes so that the inhabitants had at least some access to natural light, something that could be called weather, and—at night—to twinkling stars.
The committee had invited a chronobiologist to today’s WASPS meeting. She had written to them to point out that the agency had overlooked a serious problem in their evacuation plans. The problem lay in the different lengths of days that every planet produced. Human clocks, she had noted, are quite fussy about day length, and malentrained clocks cause huge health problems, as we know from the early days of shift work. The concerned chronobiologist, Svenja Rasmunson from the Center for Chronobiology in Tromsø, was asked to give a more detailed presentation about her concerns and their scientific background to the committee. During her talk, the committee members looked at their individual screens on the long conference table. One image showed a list of planet rotation times, corresponding to the length of the planet’s day in hours:
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