Do morning- and evening-type people really exist?

Yes, morning- and evening types really do exist; it’s not just something you talk yourself into. One of the causes is a difference in the functioning of a person’s biological clock. Lifestyle also has an effect, though, making it possible for an evening person to get up a little earlier, and a little later for a morning person.

A morning person wakes up early and easily in the morning, but by evening the curtains close and they want to go to bed early. An evening person, on the other hand, struggles to wake up on time in the morning and often doesn’t really get going until the evening. Performing well or exercising: a morning person likes to do them early in the day, but evening persons prefer to do them in the evening. The differences can be so large that a true morning person is already out of bed when an evening person is just getting in.

Can you switch from being an evening person to a morning person? No, that’s not easy. As an evening person, you can make some lifestyle changes that make it a little easier to fall asleep and wake up on time, but you will never really become a morning person. Is that a problem? That depends on whether you maintain a fixed rhythm as an evening person, because an irregular rhythm is not very healthy. Recent research shows that a regular sleep-wake rhythm is a stronger predictor of life expectancy than sleep duration.

The rhythm of sleeping and waking is regulated by the biological clock in your brain; an area of 100,000 brain cells just above where the optic nerves enter your brain. The cells in the biological clock can produce a rhythm of about 24 hours and tell the body what time it is: that it is time to go to sleep and that it is time to get up. They also generate all kinds of rhythms in your blood pressure, heart rate, and hormone levels to prepare you for falling asleep and waking up. The rhythm of the biological clock is not exactly 24 hours: in morning people, it runs slightly faster, let’s say 23.8 hours, while in evening types it runs slightly slower, let’s say 25 hours. As a result, an evening type does not receive the signal until late that it is time to go to bed or get up. However, you can move the clock a bit as light falling on your eyes in the morning speeds up the clock and evening light makes it slower.

So, an evening types’ biological clock runs slower than that of a morning type. You can adjust your biological clock by being in light and dark at the right time. It is important to maintain a regular sleep-wake rhythm and see as much daylight as possible – at least two hours – each day. For evening types, it is especially important to open the curtains immediately after waking up, eat breakfast in the light, and avoid light in the evening.