Circadian Misalignments

Image Source: Impactlab.

You may recall this post, about scientists who plan to control the body's internal clock. I09 (via Brain Pickings) discusses a new book by German chronobiologist Till Roenneberg, who argues that our social clocks and bodily clocks are not lining up and this is causing obesity, psychological stresses and physical illnesses. Roenneberg's "social jet lag" is induced by the conflicts between natural light, technology, business working hours and time spent socializing. From I09:

Just because you sleep later than your early rising friends doesn't mean you sleep longer than they do; nor does it make you lazier. And yet, the association between the time of day that a person wakes up and how proactive or driven they are is just one example of the many preconceptions that society upholds regarding sleep and productivity.

But here's the problem: these expectations might actually be working against us.

In his recently published book, Internal time: Chronotypes, Social Jet Lag and Why You're So Tired, German chronobiologist Till Roenneberg provides numerous examples of how social expectations surrounding time may be having a detrimental effect on large sections of the human population. ...

Evidence continues to pile up that the late-night schedules of shift workers clash so violently with their internal biological clocks that they actually increase their risk of obesity, diabetes, and a long list of other nasty health effects. Researchers have linked these adverse effects to discordance between the timekeeping mechanisms within our own bodies (the molecules that control the daily cycle of fat production and storage in your liver, for example) and our odd-hour work schedules.

Researchers who study metabolism call this "circadian misalignment." Roenneberg calls it "social jet lag" (a concept he explains quite succinctly in the video featured [below]). Whatever you call it, a growing body of evidence suggests that the disconnect between our internal clocks and societal clocks could be informing aspects of our daily lives ranging from metabolic disorders, to suicide rates, to alcohol consumption, to why older men marry younger women.

You can check your 'chronotype' here at Roenneberg's site CLOCKWORK.org and his contribution to the EU project to train the bodily clock here. Roenneberg's work at Munich University's chronobiology project is here.

Video Source: Youtube

Abstract for the above video: "Why are most people in industrialized societies so tired? The reason lies in an increasing discrepancy between our body clocks' internal time and the social demands on work/school days (social jetlag). Because we predominately work inside, our body clocks have become later over the years while work times have stayed approximately the same.


Body clocks use the light-dark cycle to synchronize to the 24-hr day, while society manipulates social time (e.g., time zones and daylight saving time) ignoring the internal time of an individual. The signal to fall asleep is predominantly controlled by the body clock, whereas wake-up on workdays is enforced by the social clock. As a consequence, close to 80% of the population uses alarm clocks on workdays. The more "social jetlag" people suffer from, the more likely they are to smoke, drink alcohol, and consume caffeine, and the odds are higher that they belong to the overweight/obese portion of the population."