Thursday, July 14, 2011

The after-hours mutants

Every night owl you meet will tell you the same thing: there is something magical about those late night hours when the rest of the world is sleeping. It's your time, unscheduled and undisturbed, to spend as you wish. To some, this perspective may seem lazy and immature, a luxury afforded only to those who don't have real adult responsibilities. And this may be partially true - many would-be night owls have few opportunities to enjoy the later evening hours because of work, kids, and other demands. But new research suggests that even these non-practicing night owls may be hard-wired to want to stay up late. Though sleep preferences are due in part to non-biological factors like culture, and family environment, at least 50% of the variance seems to be driven by genes, specifically something called the "after-hours mutant" which appears to prolong the circadian rhythm. As a result, evening people may find the traditional work schedule a constant battle with the snooze button, regardless of how much sleep they get.

Harvard Business Review: July-August 2010
You probably already know whether you're a morning or evening person, but if you're not sure, here are two ways to figure it out:

1) On weekends, or when you don't have to wake up at any particular time, when do you naturally wake up? If the answer is more than an hour or so different from when you wake up on weekdays, chances are you're an evening person by nature. Morning people tend to wake up just as early on weekends as they do during the week.

2) Regardless of how much sleep you've gotten, when do you find that you have the most energy? If your energy peaks in the morning and dwindles by late afternoon, you're a morning person. If it peaks later in the evening - you guessed it - you're an evening person.

The debate over whether it's better to be a night owl or an early bird has been going on for centuries, and more often than not the early birds have indeed gotten the worm, as their natural sleep schedule corresponds with traditional business hours. The stereotypical morning person arrive at the office chipper and energized, while the evening person stumbles in, coffee in hand, and stares at the computer screen for an hour before getting to work.

Research on the advantages and disadvantages of each "chronotype" has yielded mixed results, in part because it is difficult to conduct this research experimentally, making it hard to disentangle causes from consequences and to rule out mediating variables. Furthermore, the costs of being an evening person may result more from the difficulty of conforming to normal work hours, and to consequent sleep deprivation, than to anything inherent in preferring evening hours. Still, this line of research has produced some interesting findings. For example, night owls appear to be more intelligent and creative, on average, while morning people get better grades and have greater career success. Early birds may get a rush of adrenaline in the morning, but they suffer in the afternoon and evening, when they are more prone to cognitive failures. Night owls, on the other hand, are often able to concentrate long into the evening, even if they've been awake for just as long. Evolutionary psychologists have suggested that a preference for late hours may suggest a higher level of intelligence because being a night owl is presumably an evolutionary novel preference, though this hypothesis is controversial. Evening people also love to mention that President Obama is a night owl. But he also probably gets under 6 hours of sleep a night, something that most of us can't sustain. 

Whether you are a morning or an evening type, the best approach seems to be to find a way to maximize the strengths of your style (without losing too much sleep as a result), and to respect preferences that differ from your own. For example, policy makers are beginning to realize that high school students, who tend to be natural night owls for developmental reasons, should not be forced to wake up at the crack of dawn. Academics have long accommodated later sleep cycles, especially in certain fields (it's rare for a psychology class to start before 10am), but the rest of the working world has yet to catch up. 

Godinho, S., Maywood, E., Shaw, L., Tucci, V., Barnard, A., Busino, L., Pagano, M., Kendall, R., Quwailid, M., Romero, M., O'Neill, J., Chesham, J., Brooker, D., Lalanne, Z., Hastings, M., & Nolan, P. (2007). The After-Hours Mutant Reveals a Role for Fbxl3 in Determining Mammalian Circadian Period Science, 316 (5826), 897-900 DOI: 10.1126/science.1141138

Kanazawa, S., & Perina, K. (2009). Why night owls are more intelligent Personality and Individual Differences, 47 (7), 685-690 DOI: 10.1016/j.paid.2009.05.021


  1. Night owl here, and its great to hear that I am more "intelligent and creative" while my counterparts are suffering from "cognitive failures."

    A bit skeptical though, things like "optimism" and "humorous" and "stable" seem too general; it's just too easy to slap on labels like those, in other words.

    There is also a causal worry: Are night owls more creative because they stay up late, or do they stay up late because they are creative.

    Interesting stuff nonetheless.

  2. Thanks for your comment! I agree about the labels, and your concern about causality. As with other correlational research, we only know that for the participants sampled, there was an association between sleep preference and a given personality trait. We don't know the causal direction (perhaps, as you said, night owls stay up because of their creative energy), and we don't know whether a third variable, such as genetics, might be responsible for both sleep preference and creativity. Although it would be difficult to experimentally manipulate people's natural preferences, future research on the biological and developmental aspects of sleep cycle preferences will hopefully help paint a more complete picture of the origins of these differences and their potential malleability. And of course, a final caveat is that the findings reflect general patterns, but they won't necessarily be true for every individual.

  3. Our local high schools used to start at 7:45. This last spring they proudly announced that they have discovered this research and now understand this is not in the best interest of students. They have accepted the evidence, and are starting at a later hour.
    School now starts at 8 am.

  4. Thanks for your comment, Margaret!

    Yeah, I doubt 15 minutes will make much of a difference - a lot of those kids probably still have to wake up by 6:30am (especially if they take the bus), which in the winter months is before sunrise. I've heard that it's hard for schools to make major changes because of the need to align school schedules with parents' work schedules, and to leave enough time for after-school activities/ sports without cutting back on academic hours (and I'm sure there are many other considerations I'm not aware of). Despite these obstacles, it seems like it would make a huge difference for teenagers to get a couple more hours of sleep, so I hope schools can find a way to make it work.

    For readers interested in learning more about this issue, here is an APA report:

  5. Hello :) I really enjoyed this little article.
    I'm currently studying graphic design & I was just blogging about being most creative in the evening, and the inconvenience of it as I get rather tired and little sleep if I have university or work in the morning.. I googled it to discover why this was. Turns out I am an evening person.
    I don't think I could be as creative during the day, there's something about it being dark outside, the use of artificial light and the peace and quiet (even though I listen to music, if I did this during the day the creative juices just wouldn't flow)
    When I'm in university during the day, my fellow students throw ideas around that were just picked from their brain & I'm completely stuck until the evening comes around and I become more motivated.
    I find it very bizarre, however I think i'm just going to have to deal with the sleep deprivation if I intend on going somewhere within my profession!
    Thank you for an interesting read!

  6. Yes, that's definitely a dilemma for evening people who have to get up early. Getting enough sleep is important for optimal functioning as well, as Amie has discussed in other posts. But sacrificing creative time isn't ideal either. You could try starting your evening hours earlier (so that you have the same amount of time to work but it doesn't go as late) or giving yourself quiet, uninterrupted time during the day - but I know that there is something peaceful about the late hours that can't be easily reproduced during the day.

    Thanks for reading!

  7. Hey there! I've been furiously researching sleep patterns today, as I've been waging a battle with my parents for years over my sleep schedule. A new wake-up rule has now been instigated within my household, and when I asked why, their answer was simply "Because I said so," despite the overwhelming amount of evidence I've provided for them in favor of allowing my night owl tendencies.

    I too am a graphic designer, and I have the exact same issues. Night time is a time for me to do what I like, without the persistent interruptions of day time life. I'm most creative at night, and most awake after seven pm. I hope that businesses, too, will heed this research and make work schedules more accommodating to those of us who find it difficult to function before eleven in the morning.

  8. I just hate to get up in the morning...but every morning am waiting for my night to come..i want to night only..and i usually feel sleepy with a book in the morning.i feel very alert and happy from 10 pm to 2 am and biggest problem is nobody from my family can adjust with my going to marry after six months..and my would be warned me that i should get up early in trouble...early mornings...i cant imagine...wat to do