Chances are you already know whether you're a morning person or a night person (and if you don't, just ask your significant other). What you might not know is that social scientists use pretty specific—and, by academic standards, pretty casual—names for these two chronotypes. "Larks" are up and at it early in the morning, and tend to hit the sack at a respectable evening hour; "owls" are most alert at night, and typically turn in long after dark.
These labels are less an either-or than a spectrum; chronotype can shift over a person's lifetime, and recent work suggests adding two more subsets to the list: early to wake and late to bed, and late to wake but early bed. But generally speaking the larks-or-owls construct has stood the rigors of research, with evidence really growing since the development of a 19-part Morningness-Eveningness Questionnaire in the late 1970s that sorts folks into chronotypes based on things like when they'd ideally get up, how alert they feel in the morning, when they normally get tired, and so on. More involved than asking a spouse, but effective.
An exhaustive list of lessons to emerge from this line of study isn't possible (or, frankly, something that sounds fun). But we gathered some of our favorite lark-versus-owl studies from recent years and identified nine general insights worth passing along—for your late night, or early morning, pleasure.
Ben Franklin, that jack-of-all-Founding Fathers, once advocated for a lark lifestyle in a famous saying: "early to bed and early to rise makes a man healthy, wealthy, and wise." But a pair of epidemiologists at Southampton University in England—perhaps still bitter over that whole Revolution thing—directly challenged Franklin's tyranny of the morning people in a 1998 paper for BMJ.
The researchers analyzed a national sample of men and women who'd been surveyed years earlier on sleep patterns as well as measures related to, well, health, wealth, and wisdom. There were 356 larks in the group (in bed before 11 p.m., up before 8 a.m.) and 318 owls (in bed after 11, up after 8). Contrary to Franklin's decree, night owls had larger incomes and more access to cars than did morning larks; the two chronotypes also scored roughly the same on a cognitive test and showed no self- or doctor-reported health differences.
"We found no evidence … that following Franklin’s advice about going to bed and getting up early was associated with any health, socioeconomic, or cognitive advantage," the authors concluded. "If anything, owls were wealthier than larks, though there was no difference in their health or wisdom."
A lark v. owl study published the following year looked more closely at the question of brains. Psychologist Richard D. Roberts of the University of Sydney and Patrick C. Kyllonen of the Air Force Research Lab, measured the chronotype of 420 test participants then gave them two intelligence tests. Together the tasks measured vocational knowledge (e.g. mechanics and engineering), general math and reading comprehension, and working memory and processing speed.
The results, though not overwhelming, did come down slightly on the side of evening types. Night owls outperformed morning larks on most of the intelligence measures—with significant differences on working memory and processing speed. Especially interesting was that the finding seemed to hold up even when the cognitive tests were taken in the morning.
"The results indicate that, contrary to conventional folk wisdom, evening-types are more likely to have higher intelligence scores," Roberts and Kyllonen reported in a 1999 issue of Personality and Individual Differences. Wise old owl, indeed.
Evening types weren't just good at scoring on intelligence tests. They also proved to be prolific lovers—at least according to a 2012 paper in the same journal.
The study, led by Christoph Randler of University of Education Heidelberg in Germany, tested 284 male participants for their chronotype and their sexual behavior. While both morning and evening types got busy equally often, the night guys reported more total partners. This held true even when Randler and company controlled for age, extraversion, and a tendency to stay out later. Evening types were also more closely linked to infidelity; to take the bird analogy way too far: it seems owls, and not larks, breed cuckolds.
As for why night owls might close more romantic deals, the researchers wonder if "a high activity during evening and night may honestly signal a better performance in sexual activity because most sexual activity in humans takes place around bed time." That's a dubious conclusion, though we'd love to see What's your name, what's your chronotype? catch on at the bar.
In a delightful study, a research team that included a representative of the San Francisco Giants issued a morningness-eveningness questionnaire to 16 Major League Baseball players—nine owls, seven larks. The study group then paired this chronotype information with game statistics from nearly 7,500 innings during the 2009 and 2010 seasons. They reported their highly preliminary findings in a 2011 supplemental issue of Sleep.
When morning types played in early games (with start times before 2 p.m.), they batted a respectable .267. But when evening types played in night games (with first pitch after 8 p.m.), they hit a dazzling .306 as a group—nearly 30 points higher. It's worth noting owls suffered more than larks when game-time conflicted with chronotype: morning players hit eight points lower in night games (.259), but evening players hit 54 points lower in day games (.252).
Franklin's adage about morning types being healthy does seem to hold in one regard: larks might be a little less vulnerable than owls to substance abuse.
A number of studies support these connections. One analysis of 676 adults from a Finnish twin cohort found that evening types were much more likely to be current or lifelong smokers, much less likely to stop smoking, and at much higher risk for nicotine dependence as per diagnostic criteria, compared with morning folks. Another study of 537 individuals found that owls consume more alcohol than larks.
That's not a huge surprise when you consider that nightlife is conducive to drinking and smoking. What's less clear to researchers is whether evening people are more inclined to partake because they're already out late, or whether the addictive behaviors—at least in the case of a stimulant like cigarettes—keep them up longer in the first.
The tendency to drink and smoke among evening types is consistent with a broad personality trait that researchers call "novelty-seeking." Multiple studies have connected owls with that characteristic. In a 2011 paper notable for focusing on adolescents, Randler and a Heidelberg colleague discovered a link between night people and novelty-seeking already present among German teenagers (technically, ages 12 to 18).
The same research—which evaluated 346 test participants on both chronotype and a through character inventory—found that larks scored higher than owls (as well people who didn't fit in either category) in terms of persistence and cooperation. These positive traits among morning types built on other personality work from Randler showing that larks tended to be more agreeable and conscientious, and that they tend to be more proactive than owls. Showoffs.
Given that larks are generally more compliant and conformist than owls, it comes as little shock to learn that evening types seem to be worse procrastinators. A 1997 study led by veteran delay researcher Joseph Ferrari of DePaul found that trait procrastinators called themselves "night" people. Based on six days of daily task records, Ferrari and company linked procrastination behaviors with a general tendency to partake in evening activities.
That study focused on college students: night types and procrastinators almost by definition. But the finding held true in a 2008 study of an adult sample with a mean age of 50. Once again, being a night owl was associated with avoiding a task that needed to be completed, the study team (which included Ferrari) reported in the Journal of General Psychology.
The researchers also suspect that this general preference to delay tasks until night could create problems at jobs with strong daytime work expectations.
This disconnect between conventional daytime expectations and nighttime preference might make life harder for owls in general. Social scientists call this outcome "social jetlag": evening types that force themselves to wake up early and perform at their peak during the day might cause themselves some sleep loss and emotional distress. They might also be less happy as a result.
That's the argument put forth by two University of Toronto psychologists in a 2012 paper. After assessing a sample of 435 young adults (17 to 38) and 297 older adults (59 to 79) on their chronotypes as well as their current moods, the researchers found that morning people had higher positive affect across the board, compared with night people. Mood isn't the same as general happiness, but the findings may speak in part to the challenges owls face on a daily basis.
"Waking up early may indeed make one happy as a lark," the researchers conclude in the journal Emotion.
So there are clear benefits to matching someone's chronotype with that person's lifestyle, but the occasional mismatch isn't the end of the world. It might even brew some creativity, according to a 2011 study by psychologists Mareike Wieth and Rose Zacks.
Wieth and Zacks determined the chronotype of 428 test participants then randomly assigned them to a morning or late afternoon test session. During the session, the participants had to solve six problems. Some were analytical problem, which can be solved with logical thinking, and some were insight problems, which tend to be figured out via "aha" moments or bursts of creative thought.
(Brief pause for an example insight problem: An antique coin dealer gets an offer to buy a bronze coin with the date 544 B.C. stamped on one side, but instead of buying it he calls the police. Why? We'll give you a moment. No coin truly made in B.C. would label itself B.C.—that's an A.D. construct)
In the journal Thinking and Reasoning, Wieth and Zacks report that, overall, people were more successful at the analytical problems. But participants had a higher solution rate for insight problems when doing them at their non-optimal time of the day—say, an owl doing the test in morning—than at the time that aligned with their chornotype. The results lend support to the incubation theory of creativity: taking a break from a problem, often out of mental fatigue, can produce unexpected insights.
Maybe even insights about morning and night people.