Saved By The Bell: How A Late Start To The Day Affects Your Body


Do you remember what it was like to have a bedtime? Do you recall the frustration in getting home from school, going about your homely business, only to be sent to bed at a time you are told is reasonable enough to wake up in time for the early bells of school? For many, the hours that surround bed time are often spent looking angrily at the ceiling, reading, or browsing the web, in an empty search for a sleepiness that is simply not there. It’s a proper nuisance, and one which marks some of the trademark agonies of teen life: the fight between an increasingly more capable body and the social circumstances that dictate the rhythm of daily life.

It’s also a struggle most adults can find solace in, as it seems to only persist and grow stronger with the rolling of the years. Yet, since the march of time knows no brakes and there is only so much we can do to change our bodily drives, trying to change the overarching social and professional circumstances might just reveal to us ways to improve the interaction of the two that dictates our day to day.

In 2017, the city of Seattle changed their official school opening times, delaying them by 55 minutes. The first bell, which used to ring at 7:50 AM, was pushed back to 8:45 AM. A group of researchers naturally saw this as an opportunity to reach an understanding of just how much sleep, and adherence to our internal rhythms affects our output during the day. 

It’s no secret. Most teenagers, like many adults, live in a constant state of chronic sleep deprivation. In general, the developing body, from the onset of puberty to the final phases of adulthood, which generally come around the age of 25, exhibits a preference for late nights and later mornings. The biological reason for this drive is a simple delaying of sleep onset fueled by a lengthening of your circadian period. What constitutes a biological night (which is simply when your body thinks it is night), is hence pushed backwards. The developing body, slightly less sensitive to morning light because of this shift, hence struggles to rise early in the morning, shaving off a few hours of biological night and abruptly making those into day. As such, little to no teenagers are able to sustain a healthy sleep schedule (which includes between 8 to 10 hours of rest every night), especially when social circumstances imposes they rise at a time that is at a disconnect with the necessities of their bodies, as described below.

Until now, though the science has long been known, there have been no concrete studies that have related any measurable, inconfutabile outcome, to a change in the social circumstance responsible. Seattle’s choice of delaying school times by little less than an hour represented, for the team spearheaded by the University of Washington’s Gideon Dunster, an occasion too enticing to finally put the foundation of such behavioral biology to the test, in hopes of uncovering outcomes that may be useful in dictating the effect of such social circumstance well past the confusing walls of puberty. 

The effect was obvious: the study a significant increase in daily sleep by more than half an hour, changing from a median of 6 hours and 50 minutes to one of 7 hours and 24 minutes. That is to say, a later school time allowed students to sleep more. To some, particularly those particularly loving of late nights, that might come as no surprise. Seeing the effect occur on average, though, was more than one could have hoped for, given that it provides valuable data in line with the circadian hypothesis presented earlier. A later start time, then, is more suitable to the biology of the developing adult.

Since that may not be enough to really make scientific headlines, the researchers dove further, in an attempt to understand how improving the alignment between sleep timing and circadian rhythms rippled into other fields. All teachers in the school reported that their students showed an accentuated decrease in sleepiness during class hours. Most notably, however, the scientists discovered a 4.5% increase in median grades across all of the high schools that made the data available. The reasoning is clear: though we can’t strictly attribute a cause-effect relationship, attuning this alignment resulted in better performance. 

Not only that, when the scientists dove even further, and split between so-called “disadvantaged” schools and the more economically advantaged, they noticed something else of great note. Amongst the students of the disadvantaged institutions, delaying start times significantly increased student attendance and punctuality. Though an effect was also noticed in the other schools, it was ever more accentuated in this peculiar scenario, revealing one of the ways in which it may be possible to “decrease the learning gap between low and high socioeconomic groups”, say the researchers. 

But what if you’ve gone through puberty already, what can we make of these results if we are well past that developmental stage of life? Well, what is most of note in this particular case is the immensely beneficial effects of aligning biology and circumstance. As we grow old, and our body adapts to the difficulties and rhythms of daily life, it is easy to slip into situations where the drives of our inner biology are not reflected in action, and viceversa. These create vicious cycles, where one hinders the other, and viceversa, until absolute exhaustion. Prioritizing a balance between these, can, on the other hand, do wonders not simply for one’s mood, but for one’s intellectual output, even if measured in objective, standardized terms. 

For behavioral psychologists, this is a strangely giant leap, as it provides methodical evidence that modifying circumstance to sync with our bodily rhythms is not only viable, but alarmingly necessary. It flips the script, if anything, on the age old debate of working to live and living to work, promising greater and better quality of intellectual life to those who chase after this synchronism.