Postdate: 18 December 2017
The extent to which you are a morning or evening person is partly determined by your genes. This has a large effect on your biological clock. From prior research, it appears that it has something to do with your chronotype. Late chronotypes go to bed late and wake up late. With early chronotypes, it is just the other way around.
How to determine whether you are a morning or evening person? Consider your biological clock on your free days and compare it to your working days. Many people can get up in the morning without the need for an alarm clock, but there are also those who even need an alarm for waking up at a later time. It takes time for you to start the day properly, or you are at your best in the morning. Besides that, culture, environment, learned behaviour, and summer/winter time are determining your chronotype. Your biological clock affects your sleep. Someone who likes to work until the small hours has a bigger chance of a sleep deficiency. Research by biologist Christoph Randler shows that morning people are more proactive than evening people, whereby it is assumed that the 'early to bed, early to rise' principle works best.
You are not, by definition, either a morning or evening person, but you tend to be more one or the other. The majority of people fall between the two extremes or are 'forced' to be one or the other due to fixed working hours or the sleep-wake rhythms of young children. As it partially depends on learned habits and routines, you can adjust it yourself. When you stay in bed until noon on your free days, then this will not contribute to your rhythm. This is similar to having difficulties falling asleep because you think you are an evening person, while the real reason is that you are distracted by the light of a screen.
Not everyone benefits from a 9-to-5 working day or working in shifts. So it should be more about quality, and less about the working hours. Some people even prefer to work at night. Even so, you are not a typical morning or evening person throughout your whole life: this changes over the years.
‘The way we metabolise our experience of time influences our biological clock’