How are you in bed? No, we don’t mean it like that… are you the type of person who falls head-first into an Internet hole only to emerge well after midnight, or the type of person who habitually wakes up for your daily 6am jog, no alarm clock needed. But what do our night owl or early-riser tendencies say about us?
My roommates (one cat and one fiancé) are classic night crawlers. The former because she’s biologically wired to hunt while concealed in darkness (even if the only thing she’s hunting are loud toys to roll around our studio apartment), and the latter because he’s a hopeless procrastinator prone to 11pm bike rides and last-minute work binges.
Faced with their late-night antics, my usual 10pm bedtime creeps toward midnight and beyond — and, interestingly, I find I get some of my best work done during these hours. But when visiting my parents in the suburbs, I happily partake in early-bird specials and morning dog walks with the fervor of every baby boomer in a 50-mile radius. So, I don’t really fall into either camp. But, maybe, your sleeping habits are a lot more clear-cut than mine. And if that’s the case, science has a lot to say about it.
Our cycle of daily activity is regulated by what’s called a circadian rhythm. This pattern is controlled by two clusters of nerve cells in the brain’s hypothalamus called the suprachiasmatic nuclei (SCN), according to Psychology Today. Unlike my feline bestie, humans rely heavily on our vision for navigation, which explains why we are mostly a diurnal (or day-dwelling) species.
Here’s where things get interesting: scientists recently discovered that our genes actually play a role in our individual circadian rhythms. In a study of nearly 90,000 people whose genomes were decoded by 23andMe, researchers discovered 15 genes that are tied to whether you’re an early or late riser. So you could, very well, get it from your mother.
This discovery also unearthed some telling gender- and age-based patterns. More women than men (at around 48% compared to 39%) self-identified as morning people. And my anecdotal evidence of my parents’ behavior (my dad, no joke, often rises at 4 or 5am) is spot on: about 63% of those over the age of 60 prefer early mornings. Contrast that with early risers under 30 at only 24%, and you can describe early adulthood and teenage years in a single statistic.
If you’re up and at ‘em before your iPhone alarm even goes off, the study has more to say about you. This trait is also associated with lower cases of insomnia (understandable), lower instances of depression, and a more stable body weight or BMI. Morning people are also less likely to need more than 8 hours of sleep, to sweat while sleeping, or to sleep walk.
So, yeah. If you hit the hay super late, you’re more prone to all of those issues (and two thirds more likely to be diagnosed with sleep apnea). But fear not! This doesn’t mean that by definition you’re a depressed troll person. Evolutionary psychologist Satoshi Kanazawa reports that more intelligent children grow up to be more nocturnal adults. To be exact, kids with an IQ of less than 75 (which is literally rated as “very dull”) have an average bedtime of 11:40pm as young adults, while those with an IQ over 125 (“very bright”) go to bed around 12:30pm in young adulthood.
That, admittedly, is not a huge margin, but consider this evidence as well: a study of a thousand teenagers by the University of Madrid found that while early risers got better grades, night owls scored better on inductive reasoning tests, which is correlated with higher innate intelligence. Furthermore, a study of 120 men and women of varying ages indicates that those who prefer the after hours are more creative thinkers. Scientists came to this conclusion via a series of three drawing tests, in which they graded participants on originality, elaboration, fluidity, and flexibility. Night-dwellers left morning people in the dust.
You may be thinking this paints a rather bleak picture. You can either be a healthy, diligent, hard-working early riser, or a creative genius wracked with insomnia? Here’s the thing, though: most people do not fall squarely within either category (in fact, most research estimates that only 10% of the population are extreme night owls or morning people, and all of these studies ruled out individuals who graded themselves somewhere in between). So, most likely, you possess a mix of these characteristics.
And remember that research saying that our genes dictated our circadian rhythms? That comes with an important caveat: unlike other mammals, we are the only species that choose to override our natural tendencies, choosing when to go to bed and setting an alarm clock to wake up. Sure, we may only be ignoring what our bodies are telling us because we have to get to work on time (whether your style is a morning shower and leisurely breakfast or dry shampoo and coffee-to-go). But I take that as a positive. We’re the masters of our own bedtimes — except, of course, when Game of Thrones is on.