Who Wakes Up When?

Whether you’re a morning person or whether you prefer to burn the midnight oil may have a lot to do with your age and sex. That’s according to a comprehensive study in which researchers compiled twelve years’ worth of sleep diary entries from more than fifty thousand people – enough to fill a (very sleepy) football stadium.

The researchers found several patterns in how people of different ages and sexes time their sleep differently, which can have practical implications for how we think about sleep as a society.

First, the study confirmed the idea that people’s sleep shifts later in adolescence, then gradually becomes earlier again later in life. In particular, it appears that people’s night-owlish tendencies reach their apex at 19 years, after which point people start to shift back to being more morning-oriented.

Overall, men tend to have more extreme sleep schedules than women, with men being overrepresented both among extreme night owls and extreme early birds.

But it also turns out that gender impacts sleep different at different points in life. Among people under 40, men have later sleep orientations than women on average. But when people pass 40, the trend reverses, with women going to bed and getting up later. In general, younger people also have more variable sleep schedules, with older people less likely to have extreme sleep schedules in either direction.

According to the researchers, the results point to real variability in when people naturally go to sleep and wake up. Different people sleep at different times. Age and sex are two factors that influence the timing of people’s sleep cycles, but there are plenty of others.

And the researchers say it might be in our interests to do more as a society to accommodate this variability in people’s sleep schedules. For example, since teens have a later sleep orientation, there’s a real argument to be made for starting school later.

Similarly, more flexible work schedules that accommodate individual differences in sleep times could improve workers’ health, not to mention performance and safety on the job. A less sleep-deprived world is a better world!

Should we do more to accommodate different people’s natural sleep cycles? Share your thoughts below!

Image: Flickr/Bill Smith