aktivierendes Licht

Sleep, live, love: Social jet lag and its influence on interpersonal relationships and our society

Schlafen, leben, lieben: Sozialer Jetlag und sein Einfluss auf zwischenmenschliche Beziehungen und unsere Gesellschaft

In our last blog post we took a closer look at the different chronotypes and came to the conclusion that there are naturally early and late risers, larks and owls.

In this article we would now like to turn to a phenomenon that arises from these different chronotypes - the so-called "social jet lag".

But what does this term mean?

According to Wittmann et al. (2006), social jet lag is defined as “The discrepancy between work and free days, between social and biological time”. But what exactly does that mean and how can activating or calming light help us overcome this social jet lag in the best possible way?

First of all, the basic problem: Normal working hours, which usually start early in the day, are best suited to the preferred sleep-wake times of early riser chronotypes. However, late chronotypes (so-called owls) represent the majority of the population, i.e. they go to bed late and actually get up late. In everyday life, however, only bedtime is usually regulated by the biological clock. The time you get up is usually based on the social clock (the start of work).

The result: late chronotypes suffer from an extreme lack of sleep during the week and try to make up for it on the weekend. If there is such a discrepancy between the biological and social clock, scientists speak of “social jet lag”.

Social jet lag is not only unpleasant for the person affected, but can also have a significant impact on life with their partner. This condition can be extremely disabling, as those affected are often no longer able to enjoy shared activities such as having breakfast or dinner together. The reason for this is that the individual rhythm of life can differ from that of the partner due to the chronotype. This leads to a discrepancy in sleeping habits and daily routines, which in turn can significantly affect the quality of time spent together.

In a 2006 paper by Wittmann et al. The study carried out scientifically examined the phenomenon of social jet lag. The study included around 500 participants aged 14 to 94 and took factors such as chronotype, sleep quality and psychological well-being into account in the evaluation.

The findings: Late chronotypes are more mentally exhausted in the evening and experience a greater feeling of unwellness, both in relation to the current time of day and looking back over the entire week. Early chronotypes, on the other hand, only suffer from social jet lag when they stay up late at night without being able to sleep longer the next morning due to their normal circadian wake-up time. This was determined by increased depression levels during the evaluation. However, people who go to sleep and wake up at the same time on both work and off days can minimize social jet lag.

Can this social jet lag be counteracted?

Unfortunately, fundamentally it is the case that profound social changes are required to make everyday life easier for late chronotypes. However, because our biological clock is significantly influenced and controlled by light, the positive effect of light should not be underestimated.

Daylight lamps, like the HEAVN One, can help. By activating light directly in the morning, our brain is signaled that now is the time to work and become productive. In order to find peace later in the evening (even if our internal clock tells us otherwise), the HEAVN One shines in a calming, warm light and helps our body to get sleepy and to get our internal clock into the right rhythm.


Marc Wittmann, Jenny Dinich, Martha Merrow & Till Roenneberg (2006) Social Jetlag: Misalignment of Biological and Social Time, Chronobiology International, 23:1-2, 497-509,

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