The sleep-deprived among us moan about work starting too early and parties starting too late, but new research from the University of Michigan, Ann Arbor suggests the reasons for our chronic tiredness are a lot more complicated than that.

In a groundbreaking study analyzing sleep data from thousands of people using the jetlag-thwarting smartphone app Entrain, the scientists discovered that our lack of sleep is the result of a tug-of-war between society and the sun.

“One of the broadest themes of our paper is that both your internal clock and society are affecting bedtime and wake time,” Olivia Walch, who co-authored the study together with mathematics professor Daniel Forger, Ph.D., told Inverse. “But around bedtime is where we see circadian cues being most ignored.”

In her analysis of the smartphone app data, which included age, gender, amount of light, and home country, she found that while so-called “cultural factors” often dictate when we go to bed, our body clocks still wake us up — often cutting our sleep short. Complicating that further is the fact that those cultural factors — she’s talking about cell phones, e-readers, and laptops — have an effect on our circadian clock as well, confusing its ability to wake us up appropriately.

That’s because the biggest input of our circadian clocks — our body’s natural rhythms, tuned to the rising and setting of the sun — is, of course, light. The problem, Walch explains, is the fact that we live in a society where we no longer ever really experience darkness.

“All of the time, we’re exposed to light, especially at night,” Walch says. “And our phones and e-readers are acting on us through our circadian clock.” If you’re, say, up late reading a book on your iPad, your sleep is being affected on two fronts: There is the social impact of not wanting to put the book down, and there’s the circadian impact of the light getting into your body. “Your body thinks, ‘Oh, I’m getting light right now. It must be the middle of the day. They’re fighting each other in our day-to-day life.”

What are you really going to accomplish at this time, anyway? Shut your laptop.

The brain’s master clock, located in a tiny ball of neurons behind the eyes known as the suprachiasmatic nucleus, is set by the amount of light that the brain receives. When the regularity of light is thrown off — jetlag operates on the same principle — so too is the circadian clock. Scientists have long thought that the body clock is what primarily drives our sleep cycles, but Walch’s work is the first to point out what role society plays in messing with it.

Her study didn’t focus on the effects of sleeplessness, but Walch points to research that suggests that the sleep-deprived brain is, functionally, not that different from that of a drunk person. What’s especially interesting, she says, is that sleep-deprived people, much like their booze-fueled counterparts, tend to think they’re doing just fine, performance-wise.

“Your perception of how impaired you are drops lower than your actual impairment,” she says. “People will be performing terribly on cognitive tests, but when they’re rating themselves, they’ll think they’re pretty ok.”

How then, do we avoid this chronic state of functional drunkenness? Walch suggests we start by not blaming our alarm clocks and instead think about what we do to prepare to go to bed.

“We need to focus on putting computers and phones down at night and just being aware that bedtime is an important target,” she says. “Be aware of how society is affecting your decision of when to go to bed.”

Photos via Matt Cardy/Getty Images