Night Sky in the public domain from Pixabay.

Annotated Links

Are Morning People Happier? Recent research from Emotion February 2012 and summarized here in the Barking Up the Wrong Tree blog by Eric Barker, February 17, 2012, suggests that this is indeed the case.

Biological Clocks: Larks, Owls and Hummingbirds [L]eft to our natural devices, we would eat, sleep and drink (along with many more biological functions) not when we decide to, but when our biological clock tells us to. Only cultural norms and the alarm clock give us the pretense of choice by overriding our inner rhythms — and there is increasing evidence that we are paying a high cost in terms of our health. according to Leon Kreitzman in this opinion piece from The New York Times, April 21, 2009

Bowing to Body Clocks, N.B.A. Teams Sleep In Three basketball teams, the Boston Celtics, the San Antonio Spurs and the Portland Trail Blazers have dropped the traditional early morning shoot-around in favor of research on body clocks which suggests that a better night's sleep will help players more than an additional practice the morning after a big game. By Howard Beck, New York Times, December 19, 2009.

Circadian Rhythm Sleep Disorders An online tutorial from PsychNet-UK.

Dance to the (Circadian) Rhythm The consumer technology company Jawbone released data aggregated from its users tracking sleep and wake times by location. The result is a series of fascinating interactive graphs of bedtimes and total hours of night sleep by county within the United States. Some fascinating findings suggest that our circadian rhythms are more attuned to the sunrise and sunset than to what the clocks says. Posted November 2014.

Early School Starts Can Turn Teens Into “Zombies” The body clock of teenagers shifts as they get older so that they end up being sleep deprived zombies in their early morning classes. By the time [a teen] is 17 or 18, however, her body now naturally wants to stay up until 10:30 or 11 p.m. […] for biological reasons, the average teen just can’t go to sleep much before 11 p.m. Also see the lesson plan which accompanies this article here. Published by the Society for Science and the Public, September 11, 2014.

Evening-type College Students On Early Daytime Class Schedules At A Disadvantage Eveningness is associated with not only later phases of a person's sleep-wake cycle, but also with sleep irregularities, more pronounced sleep restriction during the week, and higher sleep compensation on weekends. Evening type college students may, therefore, need a sleep education that helps them adjust to imposed morning schedules, and would probably benefit from later class schedules, according to a research abstract that [was] presented on June 10 at SLEEP 2008, the 22nd Annual Meeting of the Associated Professional Sleep Societies (APSS) by Ana A. Gomes.

Examples These excerpts from Chapter 5 of The Body Clock Guide by Michael Smolensky and Lynne Lamberg provide a readable overview of these two types of personalities and give interesting examples of people (e.g. Dilbert cartoonist Scott Adams) who are one type or the other.

From the Beginning, the Brain Knows the Difference Between Night and Day The brain is apparently programmed from birth to develop the ability to determine sunrise and sunset, [according to] new research on circadian rhythms by August Kampf-Lassin and Brian Prendergast and summarized here in Science Daily, April 28, 2011.

Genetics Press release summary of a research article suggesting a genetic marker for morningness-eveningness.

Life's Extremes: Early Bird vs. Night Owls A good overview of circadian rhythm and the chronotypes of morning larks and night owls including genetic influences and sleep-phase disorders. From LiveScience, October 2, 2011, by Adam Hadhazy.

Locating the Brain’s Seasonal Affective (SAD) Center According to research published in Current Biology and summarized here for ScienceDaily, Biologists have known that variations in the amount of sunlight a person receives and her or his circadian clock play a role in the disorder. They have also proposed that the neurotransmitters serotonin and melatonin may be involved. However, they have not yet identified the underlying neurobiological mechanisms responsible. Biologists have now localized the seasonal light cycle effects that drive seasonal affective disorder to a small region of the brain called the dorsal raphe nucleus. Posted May 7, 2015.

Morningness is a predictor of better grades in college. Morningness is a predictor of better grades in college, according to a research abstract that [was] presented on June 9 at SLEEP 2008, the 22nd Annual Meeting of the Associated Professional Sleep Societies (APSS) by Kendry Clay.

Morning People Are Actually Happier Than Night Owls Not only are morning types happier than night owls during the teen and young adulthood, but they are also happier in older adulthood as well. This, according to a study by Renee Biss and summarized here in LiveScience, June 11, 2012.

Morning People (Larks) Are More Punctual Than Owls Larks arrived more punctually than Owls to their morning lectures according to research published in Current Psychology and summarized here for The British Psychological Society Research Digest, March 16, 2015.

New Work Schedule Could Cure Your Social Jetlag Many of us are walking around all the time in a fog caused by social jetlag. That's what happens when we lose sleep because our daily schedules don't match our bodies' natural rhythms. The condition can be a particular problem for shift workers, who work into the night or on a shifting schedule. Now, researchers report that sleep and workers' wellbeing could be improved if schedules took workers' biological clocks into account. This, according to new research by Till Roenneberg and published in the journal Current Biology and summarized here for Science Daily, March 12, 2015.

Night Owls and Early Risers Have Different Brain Structures Using brain scans, researchers found that night owls showed reduced integrity of while matter in the several areas of the brain, compared to early risers. From The Huffington Post'', January 2, 2014.

Night Owl or Morning Lark? Should you pull an all-nighter or wake up early to study? This blog post reviews the evidence and concludes that it all depends on your chronotype.

Obesity and the Biological Clock: When Times Are out of Joint Urgent appointments, tight work timetables and hectic social schedules structure modern life, and they very often clash with our intrinsic biological rhythms. The discrepancy results in so-called social jetlag, which can damage one's health. Among other effects, it can contribute to the development of obesity, according to a new study published in Current Biology and summarized here in Science Daily, May 10, 2012.

The Pros and Cons of Being a Night Owl Instead of a Morning Person While some research has found that early birds tend to have more positive social traits, such as optimism, night owls may have their own distinct advantages as well. From Business Insider, June 23, 2015.

The Risks of Night Work Millions of American workers fight against their circadian clocks every day, putting them — and others in their paths — in danger. Read about the latest research on the problem of and solutions for working against our circadian clocks in this this article from the APA Monitor by Michael Price, January 2011, Volume 42(1), p. 38.

Sleep deprivation may be undermining teen health Research suggests that Lack of sufficient sleep--a rampant problem among teens--appears to put adolescents at risk for cognitive and emotional difficulties, poor school performance, accidents and psychopathology. Read this summary by Siri Carpenter in the APA Monitor on Psychology, Volume 32, No. 9 from October 2001.

Sleepiness in Teens. Not Just a Side Effect of Growing Up Evidence suggests that teenagers have a later sleep-wake cycle than children, which explains why they are not tired until as late as 11 or 12 p.m. Yet, the scheduling of many high schools forces teens to rise earlier than they had to in elementary school. So how are teens getting the 9 hours of sleep per night that they need? They're not. Read about what some schools are doing to re-adjust their schedules to the erratic circadian cycles of teenagers on this website of the American Sleep Foundation.

Sleep type predicts day and night batting averages of Major League Baseball players According to research presented by Christopher Winter at the Anniversary Meeting of the Associated Professional Sleep Societies, baseball players who are morning larks have a higher batting average than night owls for day games, but lower averages for night games.

Snooze Control: Fatigue, Air Traffic and Safety Richard R. Bootzin presented his paper If Sleep is So Important, Why Do We Get So Little of It? at the 23rd Annual APS Convention earlier this month. Read about his work inspired by some recent notable near-misses of aircraft due to fatigued air traffic controllers. The problem is not with individuals but with the recovery time between shifts for shift workers according to this summary from Science Daily, April 25, 2011.

To Keep Teenagers Alert, School Let Them Sleep In The sputtering, nearly 20-year movement to start high schools later has recently gained momentum in communities like this one, as hundreds of schools in dozens of districts across the country have bowed to the accumulating research on the adolescent body clock according to this story in the New York Times published March 13, 2014.

Virtuous Cycles: Nights Owls and Early Birds New research published in Psychological Science and summarized here by Wray Herbert suggests that there is an interaction between cognitive depletion and circadian fluctuations in tiredness. That is, people are more likely to cheat when they are experience a low energy, i.e., a dip in their biological clock. This suggests that early birds are likely to make bad choices later in the day and nights owls earlier in the day.

What Personality Traits Do Night Owls Have? Morning types are more concrete, logical, introverted and self-controlled. Evening types are more creative, risk-taking, independent and impulsive according to this brief summary taken from Richard Wiseman's book "59 Seconds: Change Your Life in Under a Minute. From the Barking Up the Wrong Tree'' blog by Eric Barker, February 26, 2012.

What Were the Daily Routines of the Great Composers? Night owls or early birds - how did Mozart, Tchaikovsky and Richard Strauss structure their day? Their habits in composing, breakfast, socialising and exercise are plotted against those of other great minds in this look at the daily routines of famous creative people by Kyle Macdonald for Classic FM radio, November 2014.

Whether You’re a Lark or a Night Owl, Your Sleeping Habits Say Volumes About Your Health. A brief summary of the research on morning larks and night owls and how they differ in their disposition, breakfast habits, alarm clock use, vulnerability to jet lag, age, and more. From April 2013.

Why Sleep is Important and What Happens When You Don’t Get Enough Summarizes research on sleep and sleep disorders and explains why it is so important that we get our rest. Published by the American Psychological Association March 30, 2014.

Who Put the Lag in Jet Lag? Leon Kreitzman, an authority on questions of the body clock, like why jet lag happens and why teenagers aren’t lazy just because they sleep late. in this opinion piece from The New York Times, February 17, 2009.

You've Heard of Owls And Larks, Now Sleep Scientists Propose Two More Chronotypes Research by Arcady Putilov and his colleagues finds evidence for a high energetic group who feel high energy in both the morning and in the evening, and a lethargic group who feel sleepy in both the morning and in the evening. From the British Psychological Society Research Digest, November 5, 2014.

Assignments, Exercises, and Activities

Electronic Texts

How To Measure Circadian Rhythms in Humans From Wirz-Justice, A. (2007). How to measure circadian rhythms in humans. Medicographia, 29(1), 84-90. Provides an overview of the topic with vivid examples and graphics. Opens in PDF.

Morningness-Eveningness Scale Horne, J. A. & Ostberg, O., (1976). A Self Assessment Questionnaire to Determine Morningness-Eveningness in Human Circadian Rhythms, International Journal of Chronobiology, 4, 97-110. Opens in PDF format.

Examples and Illustrations

Dance to the (Circadian) Rhythm The consumer technology company Jawbone released data aggregated from its users tracking sleep and wake times by location. The result is a series of fascinating interactive graphs of bedtimes and total hours of night sleep by county within the United States. Some fascinating findings suggest that our circadian rhythms are more attuned to the sunrise and sunset than to what the clocks says. Posted November 2014.

Famous Writers’ Sleep Habits vs. Literary Productivity, Visualized Maria Popova, writing for Brain Pickings wonders if there is a correlation between sleep habits and literary productivity. The results of her query led to this graphic illustrating the sleep cycle of 37 famous writers and their literary accomplishments. The result suggests that having a set routine is more important for productivity that whether one is a morning lark or a night owl. Posted December 2013.

Lecture Notes

Slide Presentations

Tests, Measures, and Scales

Morningness-Eveningness Scale Horne, J. A. & Ostberg, O., (1976). A Self Assessment Questionnaire to Determine Morningness-Eveningness in Human Circadian Rhythms, International Journal of Chronobiology, 4, 97-110. Opens in PDF format.

Multimedia Resources

Dance to the (Circadian) Rhythm The consumer technology company Jawbone released data aggregated from its users tracking sleep and wake times by location. The result is a series of fascinating interactive graphs of bedtimes and total hours of night sleep by county within the United States. Some fascinating findings suggest that our circadian rhythms are more attuned to the sunrise and sunset than to what the clocks says. Posted November 2014.

Early Bird or Night Owl, Your Sleep Schedule Says a Lot About Your Personality ASAP Science presents this animated graphic presentation on sleep patterns. Early birds tend to display more positive social traits, such as being proactive and optimistic, and are less prone to depression or addictions to nicotine, alcohol, and food, Mitchell Moffit, co-creator of the series, says in the video. Night owls exhibit significantly less white matter [in their brains], and as a result, there are fewer pathways for feel-good hormones such as serotonin or dopamine to travel through, but it's not all bad for the late-nighters. In fact, they tend to be much more creative, have been found to have higher cognitive abilities, and are known to be risk-takers. Runs 3 minutes, 10 seconds.

How To Become A Morning Person The Business Insider published this info graphic summarizing the research on chronotypes, including helpful information on how to shift your body clock to be more of a morning person. Published December 16, 2014.


Page last modified by August 11, 2015, at 05:15 PM