Morning person or night owl?
Your body has a natural daily rhythm that influences when you feel alert and when you feel sleepy. Answer six questions based on your free days, not your alarm clock, to discover your chronotype.
Did you know?
- One of the best-known chronotype questionnaires, the Morningness-Eveningness Questionnaire, was published by researchers Horne and Östberg in 1976. It is still used in sleep research today.
- The 2017 Nobel Prize in Physiology or Medicine was awarded to three scientists for discovering molecular mechanisms that control circadian rhythms, using fruit flies to identify key clock genes.
- Your body temperature follows a daily rhythm, usually reaching its lowest point in the early morning hours before you wake. This natural dip is one reason people often feel coldest and sleepiest in the middle of the night.
Understanding your body clock
Your chronotype is your body's natural preference for when to sleep and when to be active. It is controlled by your internal circadian clock, a roughly 24-hour cycle that influences alertness, body temperature and hormone release. Some people are naturally early birds, some are night owls, and most fall somewhere in between.
Partly written in your genes
Research shows that chronotype is partly inherited. Studies of large groups have identified many genetic variants linked to being a morning or evening person, including genes involved in the body's clock. This means night owls are not simply lazy — their bodies are genuinely set to a later schedule.
Age changes your rhythm
Chronotype changes across life. Young children are often early risers, teenagers shift strongly toward later bedtimes and wake times, and older adults tend to become earlier again. This teenage shift is one reason some schools have experimented with later start times, reporting improvements in students' sleep and attention.
Social jet lag
When your natural rhythm doesn't match your work or school schedule, you may sleep much later on free days than on workdays. Researcher Till Roenneberg called this difference 'social jet lag', because it feels like flying across time zones every weekend. Large mismatches are linked to tiredness and poorer concentration.
The power of light
Light is the strongest signal for setting your body clock. Bright light in the morning helps shift your rhythm earlier, while bright screens and lights late at night can push it later. Spending time outdoors early in the day is one of the simplest ways for night owls to feel more alert in the morning.
Working with your rhythm
Knowing your chronotype can help you plan demanding tasks for your best hours. Early birds might tackle difficult work before lunch, while night owls may prefer to schedule creative tasks later. Regular sleep and wake times help everyone, whatever their chronotype, because they keep the body clock stable.