An individual’s natural inclination towards sleeping and waking at particular times during a 24-hour period is known as their chronotype. More commonly, we refer to this as being an early bird versus being a night owl. Thought to be coined by William Shakespeare at the turn of the 16th century, the term “night owl” describes a person who is habitually active and alert at night. Early birds, on the other hand, rise early and go to bed early, often preferring to complete tasks and activities at the beginning of the day.

Chronotypes are complex and can be influenced by a number of factors, such as genetics and age. People may possess attributes associated with either, neither, or both chronotypes, and the degree to which someone experiences the effects or behaviours of their chronotype varies from person to person.

What is an early bird?

An early bird — also known as a morning person or lark — tends to go to bed early and wake up early. They often feel they perform best physically and mentally at the beginning of the day. An early bird’s energy levels typically drop in the late afternoon and evening, and they may struggle to stay awake past a certain time of night.

Generally, early birds have an easier time acclimating to standard daytime schedules than night owls do, but they might find it more difficult to function at events that take place in the evening or night.

What is a night owl?

A night owl, also referred to as an evening person or nighthawk, stays up late and likes sleeping in. They feel at their best later in the day and have more energy at night. A night owl might feel tired if they wake up early, and they may have difficulty staying alert throughout the day.

For the most part, modern society is structured around a daytime schedule. Many jobs follow a “9 to 5” workday, and classes at schools and universities often take place during the day. Night owls — who have an innate propensity for completing tasks and doing activities in the evening — may have trouble adjusting to these patterns.

How do I figure out my chronotype?

Taking note of the time you naturally fall asleep and wake up (without an alarm clock) can help you figure out your chronotype. If you often stay up past midnight without feeling drowsy, you may be a night owl. If you feel tired shortly after sunset and have difficulty sleeping in (even when you’d like to), you’re likely to be an early bird. 

In scientific language, early birds are ascribed as having “morningness” chronotypes, while “eveningness” chronotypes are associated with night owls. Studies suggest that the majority of people fall somewhere between the two chronotypes.

What determines your chronotype?

Recent research demonstrates that a person’s chronotype is linked, in part, to their genetics. A 2019 study involving a large-scale genomic analysis of 700,000 people across the UK and US asked participants whether they were morning people or evening people. Scientists analyzed participants’ genomes to examine genes they had in common that might play a role in shaping their sleep-wake preferences.  

The results indicated that there are 351 areas of the genome (the entire set of DNA instructions found in a cell) that are known to influence whether someone is an early riser. Using data from physical activity trackers worn by more than 85,000 individuals in the UK cohort of the study, the researchers found that the genetic variants they identified could change a person’s natural waking time by up to 25 minutes.

Age can also be a factor in determining a person’s chronotype. Most children have an early chronotype but move towards a later chronotype in adolescence, peaking in lateness at around age 19. Older people generally have earlier chronotypes than younger people.

Can you change your chronotype?

Circadian rhythms — 24-hour cycles of essential physiological processes that are linked to the body’s internal clock — play a key role in regulating the sleep-wake pattern. While it’s possible to reset your sleep pattern, genetic predisposition (and other unalterable aspects, like age) make it difficult to purposefully change your chronotype. Regardless of which chronotype you have, it’s recommended to practise healthy sleep habits if you’re working towards achieving better sleep.

A key component of good sleep hygiene is a regular sleep schedule. Setting and maintaining consistent bedtimes and waking times (even on days off from work or school) can reinforce the rhythms of your biological clock and help ensure that you’re getting enough rest.

If you wish to become accustomed to getting up earlier, as soon as you get up in the morning, open the curtains to let in natural sunlight if possible or turn on artificial lights. Light acts an as important external cue to our circadian system and tells the body that it’s time to wake up. In the evenings, turn the lights in your home down earlier and avoid using devices that emit blue light. This type of light — which is naturally found in sunlight — can trick your brain into thinking it’s still daytime, and studies have shown that the use of blue-light-emitting devices near bedtime can interfere with sleep. 

Stimulants like caffeine and nicotine before bedtime can have an impact on sleep, so it’s wise to avoid these in the evenings. Heavy meals eaten close to bedtime can also make it more difficult to sleep.

Whether you’re an early bird, a night owl, or you fall somewhere in between the two chronotypes, good sleep is essential to good health. If you’re experiencing issues with sleep that are severe or chronic, consult a doctor for guidance and treatment.