Age and gender are among the top factors that affect the amount of sleep an individual can get, a new study has found.
Age was actually found to be a primary indicator of sleep timing, and it has a critical say in the differences of sleep habits across populations.
As for the role of gender, the study authors found that women plan more sleep than men.
For the study, a team headed by the University of Michigan gathered sleep information of individuals from 100 different countries using a smartphone app that decreases the effects of jetlag. They particularly looked at how age, gender, home nation and amount of light exposure affect the duration of sleep and sleeping and waking hours.
More Than Just The Daily Grind
Circadian rhythms refer to the inconstancy in behaviors and bodily mechanisms that are linked with Earth's 24-hour day. These are designated by a clump of 20,000 brain cells behind the eyes and are managed by the quantity of light, specifically sunlight, that the eyes absorb.
Experts have long recognized that circadian rhythms are the main operator of sleep schedules, even before the rise of artificial light and usual day work schedules. In the research, however, the team also looked into how other factors, including society, play a role.
Cultural tension can nullify natural circadian rhythms, particularly manifesting most notably during bedtime. Although morning routine for school influences waking times, the team found that the daily grind is not the only one.
"Across the board, it appears that society governs bedtime and one's internal clock governs wake time, and a later bedtime is linked to a loss of sleep," says study author Daniel Forger. He adds that people's waking time also depends largely on their biological clocks and not just their alarm clocks. This then creates a strife between solar and social timekeeping.
How The Researchers Conducted Their Work
For the study, the team used math modelling, a smartphone app and large data to determine the impacts of biology and society in sleep schedules.
The smartphone app called Entrain helps travelers to prevent jetlags by recommending custom schedules of light and darkness. The app works by asking the users to input their sleeping schedules and light exposure and then giving them the option to submit these data to the university.
Of course, the quality of the app depends on how accurate the data from the users are. This then encourages the users to key in information with utmost caution.
The team was able to gather information from thousands of people, and from there, they analyzed the patterns. Linked data from the analysis are put to the test in what leads to a stimulator, which is derived from the field's understanding of how light impacts the brain cells behind the eyes that manage internal body clocks. The model enabled the scientists to tune the sun up and down to see if the correlations are still true even in extreme conditions.
In the end, the authors say their study describes and customizes what may be called normal sleep. They were also able to generate hypotheses for additional laboratory investigations and suggests essential technique to thwart the sleep dilemma in the world.
The study was published in the journal Science Advances on May 6.