Researchers Use Smartphone App To Study Sleep Patterns Around The World

A team of mathematicians from the University of Michigan have made full use of a mobile app in order to collect information regarding sleep patterns of various mobile users across the globe. Through the app (Entrain, which is designed to minimize jetlag), the researchers looked into how age, gender, amount of light, and native homeland affect how much sleep people are getting around the world, as well as what time time they go to sleep and get out of bed.

The University of Michigan research team found that cultural norms can change people’s natural circadian rhythms, with the effects manifesting more clearly during sleeping hours. They also conclude that while morning mandatories like work, children, and school play a role during waking hours, they are not the sole factors. 

As explained by Daniel Forger, the man who holds faculty positions in mathematics at the University of Michigan’s College of Literature, Science, and the Arts, as well as in the university’s Medical School’s Department of Computational Medicine and Bioinformatics, signs indicate that society directly influences bedtime, a person’s internal clock dictates his waking hours, and sleeping late is usually linked with lack of sleep. 

Internal clocks, also known as biological clocks or circadian rhythms, have long been believed to be the main scheduler of sleeping hours, even since light bulbs and fluorescent lamps were invented and during the establishment of 9 to 5 work schedules. But Forger’s team posits that society and culture plays a major part, too.

In trying to determine sleeping patterns among various countries, Forger’s team found those based in Japan and Singapore typically sleep about 7 hours and 24 minutes (the shortest among countries in the world). In the other extreme, those living in the Netherlands normally sleep around 8 hours and 12 minutes (longest around the globe). 

Other findings include:

• Middle aged males sleep the least, often less than the widely suggested 7 to 8 hours
• Females sleep more than males, around a half hour more on average; women also tend to sleep earlier and rise later, with this behavior more manifest in ages between 30 and 60 years old
• People who spend considerable time in the sunlight every day are likely to sleep earlier, and likely to sleep longer compared to those who spend some time in indoor light
• As people age, sleeping habits converge -- sleeping hours were more similar among the 55 years old plus group compared to those aged under 30, which could be related to a shrinking window in which older people can fall and stay asleep