Matthew J. Edlund M.D.

The Power of Rest

Night People in the Day World

Owls vs. larks.

Posted May 30, 2018

Chad Kirchoff at pexels
Source: Chad Kirchoff at pexels

What Happens When Biology Opposes Society

Are you a night person (owl) or morning person (lark)?  You may not be sure.  The majority of people fall in between, sometimes called sparrows or hummingbirds. But if you’re a true night person, beware. 

It’s not easy working in the Lark Work World.  For owls, every work day can feel like jet lag.

It’s been known for a long time that owls have more diabetes and depression.  A new study, using the UK Biobank and carried out by Kristen Knutson and colleagues at Northwestern and Surrey universities, argues that life as an owl may not just be tougher but shorter.

What Did the Study Study?

Mortality and survival, in 423,000 people over six and a half years. It also considered the causes of mortality and overall morbidity. 

Morningness and Eveningness were mainly determined by self-report. That usually blurs the distinctions between owls and larks. So the results in more expensive and more detailed studies might possibly be worse.

What Did They Find?

Night People died at a rate 10% higher than others, including morning people. The results were consistent after controlling for the most important mortality influencing variables.

Why Did They Die Faster?

Time rules life. Body clocks time all your life and in all that you do. Possessing a night body and going to work at 7 AM is difficult. Doing it for a lifetime is more difficult.

Consider school times, work times, sports times. Jazz clubs and raves may favor owls, but not a whole lot of human activities do.

So with a body out of synch with the world, there’s more cardiovascular disease, more depression, more diabetes. That's one reason the World Health Organization often wants to consider shift work a carcinogen.

Are Owls Accommodated in Society?

No. Owls often learn to accommodate themselves. By self-report, owls are disproportionately represented among writers, jazz musicians, tech consultants, and pretty much any job where you control your time. For owl medical students, 5 A.M. surgical rounds can be torture, as are early high school class times. The truly punishing element tends to be commuter time, which policy makers infrequently consider. A school start time of 7:30 A.M. doesn’t necessarily sound so bad, but if you include time for cosmesis, breakfast, getting to the bus, getting the bus through city traffic to school, and then add in the late night body type of many adolescents, it’s no surprise teenagers often sleep through the first half of high school.

What Makes You an Owl?

Genetics. Many different genes set different times for individual body clocks. The authors make the point that there are many other environmental influences on body clocks, but usually owls are born, rather than raised. They often know their body clocks very early in life, as do their parents.

And just as with jet lag, there are people who find changing their clocks (phase shifting) relatively simple, while others find it devilishly difficult. Once again, these issues are highly influenced by your genes. Some travelers have no trouble shifting clocks traveling from New York to Beijing, while others feel “knocked out” for a week or more.

What Can Owls Do to Adjust?

Use light. Light is a multivalent drug with effects on mood, energy and immunity,  and it’s the main factor resetting internal clocks. Bright morning light sets your clock earlier; late at night light makes your internal body clocks later. Exercise can reinforce the effect.

Light boxes are now relatively cheap and easy to obtain.  People living in sunny climes like Florida and California can use abundant morning sunlight. Yet to maintain a morning shifted life when you’re an owl is not easy.

The reason is consistency is required. You have to use light pretty much every day. Engaging in consistent behaviors can prove really difficult for a lot of people (please see last week’s article).  Where there’s a will there’s a way, and many owls find it. Some use light boxes. Others walk to work in the morning.  Some do intense exercise in bright light to start their day.  Yet outside the often marginal effects of melatonin,  there are currently no effective pills for the very broad, systemic changes required to shift internal clocks. Light works. But you need quite a big dose of it, the kind provided by sunlight, and thirty to sixty minutes each morning. Lots of owls find they can’t fit that in their busy lives.

What Can Society Do for Owls?

The authors argue that owls should not be forced to work 8 AM shifts. Yet such accommodations should also be allowed for other factors, like child rearing and getting kids to school. Laws may favor labor flexibility in Scandinavia, but Americans have generally balked at the idea. Fortunately, many companies recognize that if they want to maximize their use of talent, whether by owls, women, or others, flexibility can greatly advantage them.

Bottom Line

Owls in a Lark Work World have a tough time.  They get more illnesses, often become more depressed, and die more quickly. Using timed light and exercise can make things better, but demand considerable effort.

It’s time for social, economic, and political policy makers to consider inner time.  Body clocks affect more than performance. They also impact health.

And just as we’re learning in sexual identity and behavior, one size should not be made to fit all.