Lark, Hummingbird, or Owl? The Alarm Clock Gene

It is well to be up before daybreak, for such habits contribute to health, wealth, and wisdom.  – Aristotle

Only dull people are brilliant at breakfast. – Oscar Wilde

Everyone has heard of the “night owl” and the “early bird,” but did you know that the two types have distinctly different brain structures?  Or that researchers have discovered we all have an “alarm clock” gene that activates our biological clock in the morning?

According to Michael J. Breus, Ph.D. (aka “the sleep doctor”), “Most of us have some degree of preference for late nights or early mornings. Where an individual falls on this spectrum largely determines his or her chronotype—an individual disposition toward the timing of daily periods of activity and rest. Some of us are clearly ‘larks’—early risers—while others of us are distinctly night owls. The rest of us fall somewhere in between the two.”

Current research suggests that while about 48% of people lie in that middle zone (the “hummingbirds”), approximately 36% fall in the lark (early bird) end of the spectrum, while about 16% are (night) owls. And while there are some things we can do to make minor adjustments, essentially it is what it is – our personal biological clocks are wound from birth and controlled by our genetic make-up.  There are two variants of the gene that controls our biological clocks – a long version and a short version – and as with so many of our traits, we receive one from each parent.  Those who receive one of each type become hummingbirds, but those of us gifted with two longs or two shorts become larks and owls.

In addition to sleep-time preference, a recent study by German researchers found a link between chronotype and time perspective: larks tend to be future-oriented, while owls are more likely to be present-oriented.  There is also some indication that larks may be more likely to be introverts, while owls may be more likely to be extroverts.  And some studies suggest that owls tend to be more creative and better at inductive reasoning, while larks may be more logical and analytical.

larkWhile sleep patterns may change to some extent over the life course – beginning closer to the lark end of the spectrum, moving in an owlish direction during the teen years, and then moving back towards the lark end as we age – those shifts are relative to where we began.  I am definitely a lark; I haven’t used an alarm clock in many years and naturally wake up around 4am – and then it takes quite some doing to keep me awake past 9pm!  My mother says that as a child, I was always “up with the sun,” and I can well remember how much I resented that my parents set my bedtime earlier than most of my peers (which meant often not being able to stay up to watch the TV shows that all my friends watched).  I wouldn’t believe it at the time, but I now can understand their insistence that I didn’t function well (“You get too cranky!”) whenever that bedtime was not enforced.  Later, as a teenager and young adult, I was able to “sleep in” until around 7-8am, but at no point was I ever able to stay awake much past 10pm.  And by the time I turned 40, I was back to being a very early bird.

The hummingbirds can shift their rising and retiring times by an hour or two with little difficulty, but those of us at either end of the spectrum have some challenges to overcome.

owlOwls are most likely to have “sleep debts” due to the cultural demands of the “normal” work-week schedule.  When owls work a “day shift,” it can be very difficult for them to fall asleep at night in time to get a healthy amount of sleep before their external alarm clock rings, and the sleep they do get tends to be shallow and non-refreshing.  As a result of not getting enough sleep, owls are more likely to experience “social jet lag,” which has high correlation with poor glycemic control and obesity, sleep apnea, depression, and other health issues. To help avoid these problems, owls are cautioned to avoid smoking and limit alcohol consumption; pay careful attention to their diet; try to increase exposure to natural light; and if possible, find a work situation that fits their sleep needs.  Since owls are energetic in the early evening hours, that is generally the best time for them to exercise; however, late night exercise (which many might prefer) is not recommended as it can make going to sleep more difficult.  And although it may be tough for them to get going in the morning, taking a brief walk outside in natural light as soon as possible after waking up can help them be more alert earlier in the day.

LarkLeigh Larks’ natural rhythms are more likely to be in tune with their work requirements, but less likely to fit well with the social expectations of family and friends – especially in the case of the more extreme larks, like me.  Our challenges to getting enough sleep more often fall on our free days, when social activities can lure us into staying up beyond our body’s preferred sleep hour, yet our biological alarm clock still wakes us up at our usual early time.  On weekends, I frequently find afternoon naps to be a necessity, since I’m usually up 4-5 hours (and have a good bit of housework done) before the rest of my family begins to stir – although this solution does not work for everyone, as some find naps just make them groggy.  Morning exercise routines are generally recommended for larks, although an evening walk or light stretching can help us remain alert for a bit longer than might otherwise be our norm.

The fact that we are awake early doesn’t mean that all larks are raring to go right away!  While some do “rise and shine,” research indicates that larks tend to be most productive about 3-4 hours after their natural wake-up time, most alert about 2 hours after that, and most active about 7-8 hours into their day.  I tend to be quite slow to come fully awake, and given my druthers would spend the first couple hours of every day alone with my coffee pot and a good book.  However, I have found that after about 45 minutes with a carton of yogurt and one good mug of coffee, the little Miis in my Wii Fit are acceptable first-round exercise companions, leaving a half-hour of treadmill time for the after-work re-energize hour.  It has taken quite some time, but I think I’ve finally found the routine that will help restore a healthy balance to my days.

And that, after all, is the bottom line.  Larks, hummingbirds, and owls can each make unique and valuable contributions – IF given the flexibility to utilize the strengths of their peak times.  We all need a nurturing nest and a secure perch to sing our most beautiful songs!


Like tests?  The Munich Chronotype Questionnaire ( will tell you how you compare on the spectrum to the over 25,000 others who have previously taken it.  (The results are emailed and include a chart like the one above.)

Or, if you don’t like to share personal information, here’s another:

Lark photo by kat+sam on Flickr
Owl photo by pixabay on Facebook


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