It turns out there’s a reason you function better at different times of the day, and it all comes down to biology and genetics. Dr. Michael Breus, a California-based clinical psychologist and sleep specialist known as “the Sleep Doctor,” said as much in his book “The Power of When: Discover Your Chronotype.”
According to Breus, knowing your sleep chronotype — or your natural inclination to sleep at a particular time during a 24-hour period — can help you determine when to do things like take a nap, or when you should ask for a raise.
How sleep chronotypes work
Chronotypes are genetic, linked to your PER3 gene. Your chronotype is connected to your internal body clock and circadian rhythms. Night owls have shorter PER3 genes, while early birds have longer ones. In addition to influencing the times you wake or go to sleep, the length of your PER3 gene also dictates how much sleep you need. Night owls need less, early birds need more.
Sleep researchers, including Dr. Breus, say there aren’t just two chronotypes (night owl and early bird) — there are actually four main chronotypes:
- Bears naturally sleep and wake according to the sun. They feel most energetic during daytime and have little trouble falling asleep at night. A Bear’s peak productivity occurs in the mid-morning and dips during mid-afternoon. 50% of the population falls into this chronotype.
- Wolves (or traditionally the night owl) wake up later and go to sleep later than others. A Wolf’s peak productive time is in the middle of the day, and their productivity lasts until the evening, when all other chronotypes have already logged out. 15 to 20% of the population falls into this chronotype.
- Lions (or the traditional early bird) wake up early and are most productive in the morning. Their peak lasts until noon, so naturally the Lions are tired when evening falls and go to sleep early. 15 to 20% of the population falls into this chronotype.
- Dolphins are typically light sleepers who have difficulty following a steady sleeping pattern. Dolphins awaken during the night relatively often. They are most productive from mid-morning to early afternoon. About 10% of the population falls into this chronotype.
Some people might want to change their chronotype to get into another rhythm — but science says you can’t change your underlying biological chronotype. Over time, our bodies change, and many people find themselves turning into morning people as they get older. But you can’t speed up or alter this process.
Living with your sleep chronotype
Chronotypes not only influence your sleeping times, but also your level of activity during periods you are awake. Your chronotype affects your body temperature and blood pressure.
Our world is mostly designed for Lions, or early birds. People see early birds as ambitious people, and night owls as a bit lazy. Important meetings get scheduled in the morning, and schools and businesses expect you to be active and attentive in the morning. But it’s not all bad news for night owls — there are some studies that show benefits of that chronotype:
- A 1998 study showed that night owls have a higher average income than early birds.
- A 1999 study found that night owls showed a higher level of intelligence, even when tested in the morning.
- Night owls have more sex (possibly because it is thought of as a nighttime activity).
- Stomachs of night owls process caffeine better. Their nighttime sleep is less disrupted by daytime caffeine consumption.
Your chronotype is your natural cycle. If you try to work against it, you will have a harder time falling asleep or staying awake during the day, and you’ll also experience more sleep disturbances.
Do not fight your chronotype — move with it! Go to sleep when you’re tired rather than forcing yourself to go to bed earlier or later. Schedule your most important tasks during your peak productivity periods.
But most of all, don’t give yourself a hard time about your chronotype. Whether you are a night owl or an early bird, it doesn’t say anything about you as a person. It is in your genes, and simply explains your most natural rhythm.
This article is an excerpt from my book. Interested in reading more?