and across different continents, between about 60 percent and 80 percent of us are third birds.27 “It’s like feet,” Roenneberg says. “Some people are born with big feet and some with small feet, but most people are somewhere in the middle.”28
Chronotypes are like feet in another way, too. There’s not much we can do about their size or shape. Genetics explains at least half the variability in chronotype, suggesting that larks and owls are born, not made.29 In fact, the when of one’s birth plays a surprisingly powerful role. People born in the fall and winter are more likely to be larks; people born in the spring and summer are more likely to be owls.30
After genetics, the most important factor in one’s chronotype is age. As parents know and lament, young children are generally larks. They wake up early, buzz around throughout the day, but don’t last very long beyond the early evening. Around puberty, those larks begin morphing into owls. They wake up later—at least on free days—gain energy during the late afternoon and evening, and fall asleep well after their parents. By some estimates, teenagers’ midpoint of sleep is 6 a.m. or even 7 a.m., not exactly in synch with most high school start times. They reach their peak owliness around age twenty, then slowly return to larkiness over the rest of their lives.31 The chronotypes of men and women also differ, especially in the first halves of their lives. Men tend toward eveningness, women toward morningness. However, those sex differences begin to disappear around the age of fifty. And as Roenneberg notes, “People over 60 years of age, on average, become even earlier chronotypes than they were as children.”32
In brief, high school– and college-aged people are disproportionately owls, just as people over sixty and under twelve are disproportionately larks. Men are generally owlier than women. Yet, regardless of age or gender, most people are neither strong larks nor strong owls but are middle-of-the-nest third birds. Still, around 20 to 25 percent of the population are solid evening types—and they display both a personality and a set of behaviors that we must reckon with to understand the hidden pattern of a day.
Let’s begin with personality, including what social scientists call the “Big Five” traits—openness, conscientiousness, extraversion, agreeableness, and neuroticism. Much of the research shows morning people to be pleasant, productive folks—“introverted, conscientious, agreeable, persistent, and emotionally stable” women and men who take initiative, suppress ugly impulses, and plan for the future.33 Morning types also tend to be high in positive affect—that is, many are as happy as larks.34
Owls, meanwhile, display some darker tendencies. They’re more open and extroverted than larks. But they’re also more neurotic— and are often impulsive, sensation-seeking, live-for-the-moment hedonists.35 They’re more likely than larks to use nicotine, alcohol, and caffeine—not to mention marijuana, ecstasy, and cocaine.36 They’re also more prone to addiction, eating disorders, diabetes, depression, and infidelity.37 No wonder they don’t show their faces during the day. And no wonder bosses consider employees who come in early as dedicated and competent and give late starters lower performance ratings.38 Benjamin Franklin had it right: Early to bed and early to rise makes a person healthy, wealthy, and wise.
Well, not exactly. When scholars have tested Franklin’s “gnomic wisdom,” they found no “justification for early risers to affect moral superiority.”39 Those nefarious owls actually tend to display greater creativity, show superior working memory, and post higher scores on intelligence tests such as the GMAT.40 They even have a better sense of humor.41
The problem is that our corporate, government, and education cultures are configured for the 75 or 80 percent of people who are larks or third birds. Owls are like left-handers in a right-handed world—forced to use scissors and writing desks and catcher’s mitts designed for others. How they respond is the final piece of the puzzle in divining the rhythms of the day.
SYNCHRONY AND THE THREE-STAGE DAY
Let’s return to the Linda problem. Basic logic holds that Linda is less likely to be both a bank teller and a feminist than she is to be only a bank teller. Most people solve Linda problems more readily at 8 a.m. than at 8 p.m. But some people showed the reverse tendency. They were more likely to avoid the conjunction fallacy and produce the correct answer at 8 p.m. than at 8 a.m. Who were these oddballs? Owls—people with evening chronotypes. It was the same when owls served as jurors in that mock trial. While morning and intermediate types resorted to stereotypes—declaring Garcia guilty and Garner innocent using identical facts—later in the day, owls displayed the opposite tendency. They resorted to stereotypes early in the day but became more vigilant, fair, and logical as the hours passed.42
The ability to solve insight problems, like figuring out that a coin dated 544 BC must be fraudulent, also came with an exception. Larks and third birds had their flashes of illuminance later in the day, during their less optimal recovery stage when their inhibitions had fallen. But Edison-like owls spotted the fraud more readily in the early mornings, their less optimal time.43
What ultimately matters, then, is that type, task, and time align—what social scientists call “the synchrony effect.”44 For instance, even though it’s obviously more dangerous to drive at night, owls actually drive worse early in the day because mornings are out of synch with their natural cycle of vigilance and alertness.45 Younger people typically have keener memories than older folks. But many of these age-based cognitive differences weaken, and sometimes disappear, when synchrony is taken into account. In fact, some research has shown that for memory tasks older adults use the same regions of the brain as younger adults do when operating in the morning but different (and less effective) regions later in the day.46
Synchrony even affects our ethical behavior. In 2014 two scholars identified what they dubbed the “morning morality effect,” which showed that people are less likely to lie and cheat on tasks in the morning than they are later in the day. But subsequent research found that one explanation for the effect is simply that most people are morning or intermediate chronotypes. Factor in owliness and the effect is more nuanced. Yes, early risers display the morning morality effect. But night owls are more ethical at night than in the morning. “[T]he fit between a person’s chronotype and the time of day offers a more complete predictor of that person’s ethicality than does time of day alone,” these scholars write.47
In short, all of us experience the day in three stages—a peak, a trough, and a rebound. And about three-quarters of us (larks and third birds) experience it in that order. But about one in four people, those whose genes or age make them night owls, experience the day in something closer to the reverse order—recovery, trough, peak.
To probe this idea, I asked my colleague, researcher Cameron French, to analyze the daily rhythms of a collection of artists, writers, and inventors. His source material was a remarkable book, edited by Mason Currey, titled Daily Rituals: How Artists Work that chronicles the everyday patterns of work and rest of 161 creators, from Jane Austen to Jackson Pollock to Anthony Trollope to Toni Morrison. French read their daily work schedules and coded each element as either heads-down work, no work at all, or less intense work— something close to the pattern of peak, trough, and recovery.
For instance, composer Pyotr Ilich Tchaikovsky would typically awaken between 7 a.m. and 8 a.m., and then read, drink tea, and take a walk. At 9:30, he went to his piano to compose for a few hours. Then he broke for lunch and another stroll during the afternoon. (He believed walks, sometimes two hours long, were essential for creativity.) At 5 p.m., he settled back in for a few more hours of work before eating supper at 8 p.m. One hundred fifty years later, writer Joyce Carol Oates operates on a similar rhythm. She “generally writes from 8:00 or 8:30 in the morning until about 1:00 p.m. Then she eats lunch and allows herself an afternoon break before resuming work from 4:00 p.m. until dinner around
