J.C. Lo et al/Frontiers in Neurology 2014, adapted by S. Egts
People in Western nations tend to sleep more: seven to eight hours per night on average, compared with less than seven hours in many Eastern nations. A new study suggests that differences in the timing of the natural light-dark cycle are not to blame, but rather differing schedules for work and study. People in Singapore stayed up later on work days but rose around the same time as people in the United Kingdom. Schedules were more similar on free days.