Why Winter Fatigue Is Not the Right Problem To Solve

On seasonality, its impact on the human body, and the capitalist work culture that ignores both

8 min read

Just now

Before the invention of artificial lighting, many humans slept in two shifts. The first began sometime after sunset and lasted until around midnight; the second started in the early hours of the morning and continued until dawn. The period between the two sleeps was spent on reading, talking, praying, having sex, grabbing a snack, or visiting a neighbour.

This double-sleeping pattern, also known as segmented or biphasic sleep, was first brought to wider attention by the historian Roger Ekirch in his 2001 seminar paper on the history of human sleep. What Ekirch and others have suggested as well is that the amount our ancestors slept varied across the year, depending on both the availability of natural light and the presence of things to do. In winter, with shorter days, longer nights, and the natural world largely lying dormant, you didn’t have much of either. And so, in winter, people usually worked less and slept more.

Several non-Western forager cultures, unexposed to electric lighting, actually maintained this two-sleep system well into the modern era, also sleeping longer during darker, colder months.