I stay up late because my brain is wired differently. 5 min read
by Sarah Halliday on Unsplash
I’ve always been a night owl, even in the womb. My mother would stay up late while pregnant with me, eating blueberry pie and smoking cigarettes — both of which would have deleterious effects on me decades later.
In grade school, I would hide under my covers at night and read books with a flashlight. By high school, my parents had given up trying to get me to go to sleep; my homework was done in the wee small hours of the night before it was due. I had boundless energy as a kid (undiagnosed ADD was partly to blame) and my grades never suffered as a result of my late-night preferences.
Whether a person is a morning lark or a night owl is mostly a matter of brain structure.
While early rising continues to be touted as the key to high productivity in business (and in life), those of us who love the night aren’t going to be persuaded to change our ways anytime soon. Frankly, we can’t.
We all have a biological “body clock” that is set to various environmental signals which influence our behavior as well as our physical and mental energy. The clock is run by proteins found in the tissues of every organism from fungi to fruit flies to human beings. These proteins respond to changes in light taken in by the eyes, or by specialized cells in plants and fungi.
As light increases over the course of the day, the production of melatonin in the brain is shut down and most of us feel more energetic. As afternoon approaches, the daylight begins to fade; it’s not apparent to us but our brains notice and begin increasing melatonin production. This is why many people get sleepy in the late afternoon. By the time it’s full dark, melatonin levels are beginning to peak and most people are feeling sluggish and ready for bed.
This pattern of rising and falling energy levels are called circadian rhythms. In addition to influencing sleep patterns, circadian rhythms can also influence hormone release, body temperature, hunger, and more. Much research is being done on how disruptions to our natural rhythms can alter everything from our emotional state to our ability to problem solve and make decisions.
Researchers are discovering interesting connections between our body clocks and sugar metabolism. Metabolic disorders such as diabetes and obesity have long been suspected of being linked to problems with biological clocks, and the recent discovery of a light-sensitive protein in the liver called cryptochrome supports this theory. Sugar metabolism happens in the liver, and the presence of a light-sensitive protein there implies a relationship between light-exposure and sugar breakdown in the body.
The most troubling concern of circadian rhythm disruption is sleep problems. An estimated 70 million adults in the US suffer from sleep disorders, and poor sleep has been linked to an increased risk for chronic diseases such as high blood pressure, diabetes, depression, and cancer. Sleep disorders can also affect our behavior, making us aggressive, erratic, and depressed. Physically, we become clumsy and slow to react.
Many people who fly experience the exhaustion and disorientation of jet lag. Jet lag isn’t just a perception in our brains, it’s a physical reset that has to occur when we gain or lose time flying long distances. Similarly, daylight saving time has long been blamed for increased accidents and poor decision making that occurs each time we move the clock up an hour. That short time frame is enough to cause serious consequences in some people.
Perhaps most interesting of all, understanding circadian rhythms could potentially have agricultural applications. Being able to influence when plants flower and set seed (which is often dependent on light levels) could impact the harvests of grain crops such as rice, barley, and wheat. The egg-laying inclinations of chickens and farm-raised fish could also potentially be manipulated.
Seasonal Affective Disorder (SAD) is a serious problem for up to 10 percent of people, with the highest incidence occurring at higher latitudes around the world. Also referred to as winter depression or “winter blues”, SAD can cause profound depression, apathy, lethargy, and overeating. I suffer grievously from SAD and must receive medication when winter rolls around.
Brain differences between larks and owls
A recent study uncovered an interesting dichotomy between students and teachers. Less than 30 percent of students tested performed best in the early morning. The majority were better able to learn in the early afternoon.
Most teachers, on the other hand, are morning people and tend to experience a slump in energy after around 1 pm.
Additionally, about 13 percent of students were identified as genuine night owls, able to absorb difficult material in the evening hours.
Because our preference for nighttime is genetic, telling night owls to “get up earlier” or “learn to love morning” isn’t helpful.
Differences in brain matter can be seen on MRIs between morning people and night owls. Specifically, the brains of night owls exhibit lower and less intact amounts of white matter in the frontal and temporal lobes, cingulate gyrus, and corpus callosum. These differences are measurable and immutable.
Night owls also tend to experience what is essentially a chronic form of jet lag accompanied by sleep disturbances, vulnerability to depression, and higher consumption of nicotine and alcohol.
While these differences in brain structure seem dire, most of us learn to compensate for our differences by the time we’re in high school. We generally score as well on standardized tests and are every bit as successful as our early-rising peers.
Because our preference for nighttime is genetic, telling night owls to “get up earlier” or “learn to love morning” isn’t helpful. With few exceptions, we can’t simply change our ways.
Whether a person is a morning lark or a night owl is mostly a matter of brain structure. Identifying and working with a person’s natural tendencies could result in more productivity, better learning, and more effective teaching strategies.
Rather than espousing a particular lifestyle as the “key” to success, responding to people’s natural cycles and tailoring training to work within those boundaries will be more effective for the learners and the trainers.