2016 was an iffy year for facts. And as the election progressed, our sleep fell by the wayside, too — at least, according to Fitbit data. Nonetheless, researchers pumped out facts about sleep all year long, filling our newsfeeds with experimental studies and sleep-habit polls that emphasized how far sleep science has come in its 63-year life and how much we still don't know about the neurobiological process and culturally varied health practice that we all do. (Some better than others.) So, as we prepare to put 2016 to bed, here are 9 things we learned this year about sleep.
1. "Morning-person genes" are a thing
The genetic-testing company 23andMe analyzed the genotypes of 90,000 people (make that 90,000 people who were 23andMe customers, identified themselves as morning people and were of European descent) and found 15 DNA mutations shared by enough of the participants to constitute statistical significance. The study wasn't the first to explore the genetic basis of human chronotype (i.e., whether you're an up-and-at-'em type or a member of the late-to-bed crowd), but it was the first to do so on such a large scale.
2. Sleep loss hurts the economy
Insufficient sleep could be responsible for an annual economic loss of up to $411 billlion a year in the US alone, according to a RAND Corporation report. Why? Underslept workers make for sluggish, error-prone workers: The US loses about 1.23 million workdays a year, on account of scant sleep, RAND estimated.
3. People associate sleep-deprived faces with dull minds
Forget "beauty sleep," a concept that's probably done more for night-cream sales than sleep health. We're all about "brilliance sleep" these days. According to one UK study, people appear less intelligent when they skimp on sleep than when they log a normal night's rest. Researchers were able to attribute perceptions of intelligence to a facial change associated with tiredness: droopy eyelids. But, insomniacs take note: A different study found that insomniacs think they look more exhausted than other people think they do.
4. Daylight Saving Time isn't a time of penal leniency
Springing ahead for Daylight Saving Time has been associated with an uptick in car accidents and heart attacks. In both cases, sleep loss is thought to be a factor. Thanks to a 2016 study, we can add to that list the knowledge that judges hand out harsher sentences on the day after DST, which is apparently now called "Sleepy Monday," than on any other day of the year.
5. Just thinking about our phones at night might keep us up
It's by no means news that nighttime electronic use and sleep don't go together. But a meta-review of recent research suggests the trend bears out — in children, specifically — even when kids don't actually use devices at night. Merely having access to a (turned on) phone in the vicinity, the paper found, corresponds to shoddy sleep. The verdict? The 2/3 of kids who sleep with their phones turned on should hit "off" before they nod off, which seems like a suggestion that American teens will totally heed.
6. Sleep-deprived people are probably easy to hoodwink
In one experiment, sleep-deprived participants were more likely than their well-slept counterparts to accept falsified versions of their first-hand experiences — akin to interrogation subjects signing false confessions. Similarly, another study found that underslept people are more open to advice (than the well-rested are), whether or not that advice comes from a reliable source. Not that we should assume lab experiments necessarily translate to real-world scenarios, but we do have a president-to-be who claims he hardly sleeps (and exhibits trademark signs of sleep deprivation) and has proceeded to appoint fanatical ninnies as advisers...
7. Sleep might help us escape traumatic memories — or not
The evidence goes both ways. In one study, participants who went to sleep after watching a disturbing video had fewer, less intense memories of the video than participants who were forced to stay up afterwards. Sleeping emerged as a potential tool for processing trauma.
But, a different study suggested that it's harder to un-see gruesome images (think: mutilated bodies) if you nap after taking a gander at them. Participants in this study either napped or stayed up after viewing said photos. The next day, the napping group had less success erasing the photos from their minds than non-nappers and exhibited brain activity that suggested they'd already started converting the photos into longer-term memories during their naps.
8. Bearded dragons sort of sleep like us (and this matters)
Much to scientists' surprise, the leathery little creatures experience a simplified version of human-esque "brain sleep," meaning they sleep in stages marked by distinct electrical brain activity patterns. Until researchers at the Max Planck Institute for Brain Research figured this out, the who's who in sleep research thought brain sleep was confined to mammals and birds. But the fact that they were wrong means that sleep probably has much deeper evolutionary roots than previously assumed.
9. The cognitive benefits of napping might depend more on the heart than the brain
Some people seem to reap the cognitive benefits of a nap more than others, and figuring out why is an ongoing quest. In one study, researchers presented evidence that the autonomic nervous system, which controls involuntary functions, including heartbeat, breathing and digestion, regulates the degree to which napping helps different people learn and memorize information.