Benjamin Franklin once said, “Early to bed
and early to rise makes a man healthy, wealthy, and
wise.”_________ in Franklin’s time most people
________ in an unconsolidated fashion: They
went to “first sleep” shortly after the sun went
down, and woke four or five hours later for a few
hours of activity before returning to “second
sleep.”
Industrialization and electric lighting put the
unconsolidated sleep pattern to rest, so to speak,
and today most adults are expected to work from
mid-morning to mid-evening and, if they’re very
lucky, sleep a solid eight hours from night to
morning. This is easier for some than others.
Mounting research suggests that differences in
lifestyle, personality, brain functioning, and even
brain physicality define two distinct chronotypes
(a person’s characteristic sleep pattern), which
could roughly be defined as “night owls” and
“morning larks.” Morning larks, those who
naturally wake up early and are energized in the
pre-lunch hours, are more suited to the typical
work schedule, while the propensities of night
owls put them at odds with it, leading them to
suffer from chronic social jetlag.
Only an estimated 10 percent of the global
population are morning larks, and roughly twenty
percent are night owls, with the rest of us falling
somewhere in between. Night owls are more
prone to depression and are more likely to smoke
and drink, and while they’re potentially smarter,
their academic abilities fall short of early birds
(possibly because they were half-asleep for most
of school). It gets worse: A study published in 2013
found that night owls are more likely to have a
cluster of personality traits known as the “Dark
Triad” — narcissism, Machiavellianism, and
psychopathy. Morning larks, conversely, have
been found to be more moral.
One’s circadian rhythm does change over time
— babies are often up at dawn, while teenagers are
zombie-esque until the afternoon — and there are
certain things you can do to adjust your natural
rhythms, such as avoiding light in the hours before
bed, seeking light upon waking, and regimenting
sleep and wake time. But there’s a great deal of
evidence that our essential propensity for larkness
or owlishness is rooted in genetics. Genetic
variation can affect a person’s sleep and wake
cycle by up to an hour, and, gruesomely, can help
predict what time of a day a person will die.
One thing both groups (and those of us in
between) have in common: We probably aren’t
getting enough sleep. A December, 2013 Gallup
poll found that Americans average less than seven
hours of sleep a night — more than an hour less than
Americans slept per night in 1942. From 2006 to
2011, the market for over-the-counter sleep aids
grew 31 percent.
Adapted from: World Science Festival | September 11, 2014 http://theweek.com/article/index/267811/is-there-really-such-a-thingas- a-morning-person.
The words roughly (line 27) and prone (line 30) in the passage are closest in meaning respectively to
