The Willpower Instinct: How Self-Control Works, Why It Matters, and What You Can Do To Get More of It

GAIN WILLPOWER IN YOUR SLEEP!
If you are surviving on less than six hours of sleep a night, there’s a good chance you don’t even
remember what it’s like to have your full willpower. Being mildly but chronically sleep deprived
makes you more susceptible to stress, cravings, and temptation. It also makes it more difficult to
control your emotions, focus your attention, or find the energy to tackle the big “I will” power
challenges. (In my classes, there’s always one group that immediately recognizes the truth of this
statement: new parents.) If you are chronically sleep deprived, you may find yourself feeling regret at
the end of the day, wondering why you gave in again to temptation or put off doing what you needed to
do. It’s easy to let this spiral into shame and guilt. It hardly ever occurs to us that we don’t need to
become better people, but to become better rested.
Why does poor sleep sap willpower? For starters, sleep deprivation impairs how the body and
brain use glucose, their main form of energy. When you’re tired, your cells have trouble absorbing
glucose from the bloodstream. This leaves them underfueled, and you exhausted. With your body and
brain desperate for energy, you’ll start to crave sweets or caffeine. But even if you try to refuel with
sugar or coffee, your body and brain won’t get the energy they need because they won’t be able to use
it efficiently. This is bad news for self-control, one of the most energy-expensive tasks your brain can
spend its limited fuel on.
Your prefrontal cortex, that energy-hungry area of the brain, bears the brunt of this personal energy
crisis. Sleep researchers even have a cute nickname for this state: “mild prefrontal dysfunction.”
Shortchange your sleep, and you wake up with temporary Phineas Gage–like damage to your brain.
Studies show that the effects of sleep deprivation on your brain are equivalent to being mildly
intoxicated—a state that many of us can attest does little for self-control.
When your prefrontal cortex is impaired, it loses control over other regions of the brain.
Ordinarily, it can quiet the alarm system of the brain to help you manage stress and cravings. But a
single night of sleep deprivation creates a disconnect between these two regions of your brain.
Unchecked, the alarm system overreacts to ordinary, everyday stress. The body gets stuck in a
physiological fight-or-flight state, with the accompanying high levels of stress hormones and
decreased heart rate variability. The result: more stress and less self-control.
The good news is, all of this is reversible. When the sleep-deprived catch a better night’s sleep,
their brain scans no longer show signs of prefrontal cortex impairment. In fact, they look just like the
brains of the well-rested. Addiction researchers have even started to experiment with sleep
interventions as a treatment for substance abuse. In one study, five minutes of breath-focus meditation
a day helped recovering addicts fall asleep. This added one hour a night to their quality sleep time,
which in turn significantly reduced the risk of drug use relapse. So for better willpower, go to sleep
already.
WILLPOWER EXPERIMENT: ZZZZZZZZZZ
If you’ve been running short on sleep, there are many ways to recharge your self-control. Even if
you can’t get eight hours of uninterrupted sleep every night, small changes can make a big
difference. Some studies show that a single good night’s sleep restores brain function to an
optimal level. So if you’ve had a week of late to bed and early to rise, catching up on the

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weekend can help replenish your willpower. Other research suggests that getting enough sleep
early in the week can build a reserve that counteracts sleep deprivation later in the week. And
some studies suggest that it’s the number of consecutive hours you spend awake that matters
most. In a crunch, taking a short nap can restore focus and self-control even if you didn’t get
much sleep the night before. Try one of these strategies—catching up, stocking up, or napping—
to undo or prevent the effects of sleep deprivation.

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