The Science behind Night Owls
Are you a Night Owl or Early Bird?
J. C. Lai
Having stayed up until late hours throughout my whole life, I have always believed that my poor sleep habits were a mixture of unhealthy daily habits and poor self-discipline. However, to my surprise, our sleep preferences are actually largely predetermined by our genetics and are dictated by the circadian rhythm located in the hypothalamus of our brains. This vital function of our body is responsible for controlling our sleep cycles by releasing the sleep hormone of melatonin which is responsible for making us tired. The varying times that melatonin is released, according to our individual bodies and genetics dictates if we are either early birds or night owls.
From an evolutionary standpoint, our varying sleep cycles make a lot of sense. For most of human history, having individuals with different sleep habits would allow for better protection of a group or tribe from diurnal or nocturnal predators. However, society has made this a problem in recent decades, as most societal activities are concentrated between 9am and 5pm, putting night owls, which accounts for an estimated 30% of the global population, at a clear disadvantage.
This phenomenon has been coined by researchers as ‘Social Jetlag’, describing the discrepancies between biological time, determined by our internal body clock, and social times, dictated by social obligations such as school and work. Think of this as the normal jetlag you feel during a holiday but recurring every single day. Research has found that this chronic sleep deprivation has significant health, social, and academic implications, as our body’s circadian rhythm is not being followed.
The health implications for being a night owl who doesn’t abide by their circadian rhythm is severe. A 2018 study by Houston Methodist has found that for every hour our circadian rhythm is out of sync, the risk of obesity, high blood pressure, diabetes, sleep apnoea, and coronary heart diseases increases by 33%. In another study, the risk of depression for individuals whose circadian rhythm is more than two hours off rises dramatically, revealing that the health implications are not only physical but also mental. Moreover, German research institution Forschungszentrum Jülich found that night owls exhibit significantly less white matter within their brains, which is critical for carrying out pathways for feel good hormones such as serotonin and dopamine.
To make matters even worse, the disadvantages for night owls also extend socially and academically. The University of Texas found that night owl students recorded lower overall grades at school, as lack of sleep puts a toll on brain functioning in the early hours of the day. Furthermore, night owls tend to display less positive social traits such as being proactive and optimistic when compared to early birds.
Despite its downsides, researchers have also found many significant upsides to being a night owl. The University of Liege in Belgium found that night owls remain mentally alert for a much longer period of time compared to early birds and may even perform better after 10 hours of being awake, ultimately getting more work done at the end of the day. Researchers from the University of Madrid also found that night owls tend to have higher IQs and test higher in general intelligence. Furthermore, despite night owls lacking in white matter levels in their brains, they make up in cortisol levels in their brains, which gets a body ready to face immediate threats, contributing to higher risk-taking behaviour which studies show leads to higher entrepreneurship skills and more financial gain.
To preserve the advantages of being a night owl and limit the disadvantages it brings, health experts recommend that we night owls maintain a healthy diet to repair the damages being made to our bodies, and to take naps frequently throughout the day to offset the sleep deprivation encountered overnight.