Is there a scientific explanation behind a small proportion of the population who suffer from seasonal mood disorders, which are particularly severe in winter? Is it because our biological clocks don’t keep pace with waking hours in winter? Can shorter working hours in winter improve mood? Research on biological clocks supports this explanation that the working hours of modern life in winter are inconsistent with the biological clock.
Greg Murray, a professor at Swinburne University in Australia, says that in theory, dim visible light in winter mornings encourages so-called phase delays, which are why our biological clocks lag in winter, which is one reason why we don’t get up in winter.
Studies have also shown that we need or desire longer sleep in winter. A study of pre-industrial communities in South America and Africa found that these communities sleep an extra hour in winter. They are located in the equatorial region, and the effects are more pronounced in colder and darker areas during the winter months.