South African teens among the world’s grumpiest in the morning

Two teenage sisters. One household. A yin-yang of moods.

Durban teen Colleen Simon‚ 17‚ loves the quietness of early mornings and‚ according to her mother Melani‚ is a "breeze" at sunrise.

Her stepsister Kaylise‚ 17‚ on the other hand hates the sun on her face and refuses to wake up‚ forcing her mom to throw water in her face to get her out of bed.

She is amongst thousands of South Africans found to be the among the world's grumpiest teenagers at daybreak.

According to Sleep Cycle - a Swedish smartphone application that analyses a phone’s accelerometer to identify sleep phases by tracking movements in bed - South African teenagers' morning mood levels dropped drastically in August.

Most of the more than 55‚000 local teenage users used the angry emoji to rate their mood immediately after waking up. The grumpiest teens‚ according to the app‚ were in Turkey‚ Austria‚ Poland‚ Brazil and South Africa. The happiest hailed from Saudi Arabia‚ Ireland‚ Russia‚ New Zealand and Norway.

Local sleep experts attribute the mood swing in August to the start of the new school term.

Clinical neurophysiologist Baxolele Ngcemu said teenagers generally suffered from delayed sleep phase disorder‚ particularly after school holidays.

"This is caused by them being allowed to sleep a bit later during the holidays than they normally would during mid-term. This disorder basically means they would have 'shifted their body clock' by a few hours which then makes it difficult for them to be wide awake early in the morning."

While adolescent hormones can be blamed for volatile friend to fiend mood swings‚ science can also share some of the responsibility for grumpy teens.

University of Cape Town sleep scientist at the Sports Science Institute of South Africa‚ Rob Henst‚ said teenagers were naturally evening people.

They felt tired later in the evening and become alert later in the morning compared to older folk.

"This is caused by their innate circadian clock‚ but also because of their social life‚ which affects their circadian clock. When a teenager is allowed to go to bed and wake up at their preferred time - which would have happened in July during the holiday - they may go to bed at a time at which they feel tired‚ and they may get up at a time they feel more alert."

The teenagers would have thus felt well rested and in a good mood in July.

"But at the time the teenager was still asleep in July‚ the teenager in August must be awake and get ready for school‚ this is the second reason a person may feel tired. This may explain the poor mood of the teenagers in South Africa when schools start again‚" said Henst.

And contrary to the stereotype that girls are more cantankerous‚ boys are more likely to be crabby on school mornings.

"Teenage boys are more likely to be evening types than teenage girls; as a result boys may get slightly less sleep and are more likely to wake up from deep sleep‚ which could be a reason for them to feel more groggy and grumpy in the morning‚" Henst said.

To parents' relief‚ moods improve when the body clock shifts once school is in full swing.

But South African teenagers are still not getting enough sleep to put a spring in their step every morning.

Henst said a study found that local teenagers slept about seven-and-a-half hours on school days and just below eight hours on weekends. The American National Sleep Foundation recommends that teenagers sleep between eight and 10 hours a day.

"In most cases‚ insufficient sleep in teenagers is self-induced. The teenager goes to bed too late or chooses to perform other activities in bed such as watching TV or being on social media‚" added Henst.

SLEEP TIPS FOR TEENAGERS:

• Go to bed at a time that would allow you to sleep for at least eight hours a night.
• Go to bed at that same time every night.
• Avoid exposure to light‚ also from electronic screens‚ in the evening.
• Avoid drinking caffeine-containing drinks such as soft drinks‚ black tea‚ coffee and energy drinks after 3pm.
• Don’t pull an all-nighter to study. Sleep is an essential part of memorising school content and cannot be skipped. - Sleep scientist Rob Henst 

• This article was originally published in The Times.