I spent most of my graduate school years in a state of sleep deprivation. There was just so much work to do—tests to study for, papers to read through, and a dissertation to get done. At night, I stayed up as late as copious cups of coffee would keep me awake, and I set my alarm clock for 4:00 AM to get an early start on the next day. After a few hours of pre-dawn study, I headed to my 8:00 AM statistics class. Finding a seat in the back, I promptly fell asleep.
Since then, I’ve learned the importance of getting a good night’s sleep. Without it, I’m a lousy teacher, I understand little of what I read, and I’m incapable of writing anything coherent. Most people understand they’re cognitively impaired when they’re not well rested. That groggy, listless, disoriented feeling is something we’ve all experienced at one time or another as we try to slog through the day after a sleepless night.
What most people fail to realize, however, is that lack of sleep can have a subtle but important impact on their social life as well. In a recent article, psychologist Amie Gordon and her colleagues at the University of California, San Francisco argue that our sleep life and social life are intertwined. As our sleep suffers, so do our relationships, and likewise, negative social experiences can keep us from getting the sleep we need.
Many people think of sleep as a time when you “recharge your batteries.” Just as you can still use your smart phone or laptop even if it’s not fully charged, so you can function just fine through the day even if you didn’t get a full eight hours of sleep the night before. Or so goes the common way of thinking about sleep.
However, this “battery” metaphor completely misses the true nature of sleep. Instead of being a time when you lie passively in the dark as your body replenishes its energy supply, sleep is in fact a highly dynamic process. You may be unconscious, but your brain is very busy during those wee hours of the morning—sorting through memories and tidying up the clutter of the previous day’s experiences. Instead of recharging your battery, you’re actually engaging in mental maintenance as you sleep.
Not all sleep is the same. As you go through the night, your brain cycles through four stages of sleep. These include the light sleep of stages 1 and 2 as well as the deep sleep of stage 3. But most important of all is rapid eye movement (REM) sleep, the stage when dreaming takes place. Most people need about two hours of REM sleep per night to feel fully rested and cognitively alert the next day, no matter how many total hours of shut-eye they got. This is why people differ in how much total sleep they need.
In fact, just considering the time between going to bed and getting up isn’t a good measure of how much sleep you actually got, nor is it a good indicator of the quality of that sleep. Some people take longer to fall asleep than others, and all us wake up several times during the night—whether to go to the bathroom or just to shift position—even though we may not remember these waking episodes the next morning. In the laboratory, researchers can measure a person’s sleep efficiency—that is, the amount of actual sleep obtained during a period of time. However, your own subjective perception of how well you slept is a pretty good indicator of your sleep quality, regardless of how many hours you were in bed.
Furthermore, researchers have found that daily rhythms are important as well. “Morning people” truly are more alert early in the day, while “evening people” are more alert later. You should assess whether you’re a morning or evening person and arrange your activities accordingly, if possible.
Although the cognitive effects of sleep deprivation are widely known, few people—whether psychologists or laypersons—pay much attention to the “social side of sleep,” as Gordon and colleagues call it. They point to three areas that are known to be impacted by lack of sleep, namely close relationships, person perception, and social stress.
Close relationships. In Western culture, people prefer sleeping alone in their own beds, with the main exception being romantic partners, who typically sleep together. However, in other cultures around the world, communal sleeping is common, if not the norm. An entire extended family may snuggle up to conserve heat through the cold night. And even non-family members may sleep together—of course, with none of the sexual connotations that term implies in the West. Once when I was teaching in Japan, I went on a faculty retreat to a hot spring resort, and we all slept on futon mattresses laid on the straw-mat floor of one large room. (Co-sleeping promotes group bonding, I was told.)
Sleep has a big impact on our social relationships, especially our most intimate ones. When one partner has slept poorly the night before, there’s more conflict in the relationship the next day. This is because we have less empathy when we’re sleep deprived, and we’re less likely to engage in effective conflict resolution behaviors. What’s more, even the well-rested partner will show a decrease in empathy when dealing with their sleepless spouse, as if sleep deprivation were a contagious condition. Furthermore, couples report having more difficulty sleeping when they’ve experienced conflict with their spouse, especially late in the day. Thus, couples can easily fall into a vicious cycle of relationship conflict and poor sleep.
Person perception. To effectively interact with others, we need to accurately read their facial expressions of emotion. Yet people who are sleep deprived have a lot more difficulty doing this. After a sleepless night, research participants were less accurate at judging the emotions of happiness or anger in pictures of strangers, compared with their performance on this task after a good night’s rest. In addition, people are more likely to engage in stereotypic and biased thinking when they haven’t had enough sleep. The ability to read the emotions of unfamiliar people and to inhibit prejudiced thinking is essential to smooth functioning in most workplace environments, so not getting enough sleep can impact your job performance as well.
Social stress. Experiences such as conflict with a spouse or family member, being discriminated against, or feeling rejected, can make a good night’s sleep hard to get. Although stressful social situations are inevitable, our ability to cope with these negative experiences depends on how well rested we are. Emotion regulation is a process in which we re-evaluate our feelings and try to put them in proper perspective. But emotional regulation requires intense effort, which may simply be out of reach if we haven’t been sleeping well. Once again, we see the vicious cycle of sleep deprivation and social conflict.
According to Gordon and colleagues, more than two-thirds of American adults don’t get as much sleep as they need. Americans are busier at their jobs than ever before, but they also pad their time with leisure activities—competitive sports, thrilling action movies, and high-adrenaline online games—that can induce more stress than they relieve. The impact of sleep-deprivation on physical and mental health has long been understood. Now we know it can damage our social relations as well, sending us into an even deeper spiral of social conflict and sleeplessness. It’s time to turn off the TV, shut down the computer, put away the smart phone—and get a good night’s rest.