The Need For Zzzz

Lack of sleep affects our perception of work stress and levels of absenteeism

The essentials

We underestimate the restorative power of sleep at our peril, says Erica Carleton, postdoctoral research fellow at Ivey Business School. As part of her PhD research at Smith School of Business, Carleton conducted three studies examining the connection between sleep and work stress, leadership behaviour, and work withdrawal. While it is well known that work stress affects sleep, she found that the opposite effect — sleep affecting work stress — is even stronger. In her study, a lack of sleep led to a rise in abusive supervision, even after a single night of unsatisfying sleep. And she noted a connection between lack of sleep and work withdrawal behaviours such as partial absenteeism (at work but not working), absenteeism, and work neglect. Carleton found no impact of sleep on transformational leadership.

In a culture that often rewards busy-ness and productivity, we sometimes wear our sleep deprivation as a badge of honour, striding in after a mere four hours of sleep, espresso in hand, smugly declaring, “I’ll sleep when I’m dead.” But when sleep and work conflict, what path should we choose?

As part of her PhD research at Smith School of Business, Erica Carleton, now a postdoctoral research fellow at Ivey Business School, conducted three studies examining the connection between sleep and work stress, leadership behaviour, and work withdrawal. The common conclusion: don’t underestimate the restorative power of sleep.

Our drive for sleep is at least as strong as our desire for food or sex, Carleton says. While we sleep, there’s a reorganization of neural activity that is crucial for brain function. When that neural activity is disrupted, though, so too are our lives.

Consider stress. While there has been extensive research on how stress affects sleep, not much research exists on the reciprocal relationship going the other way: how sleep, or lack thereof, affects people’s perceptions of their stress levels at work.

“Work stress affecting sleep is a very established relationship,” says Carleton. “However, in my study, I found that the relationship of sleep affecting how we perceive our work stress is stronger than the work stress affecting sleep relationship.”

In other words, if your work keeps you up at night, you’re likely to feel that pressure even more strongly the following day. For those whose sleep is affected by stress at work, it can be a dangerous cycle — for both employees and employers. “There’s literature around the cultivation of resources where, when you lose resources, you keep losing more and you can’t regain them,” Carleton says. “It’s a spiral of loss.”

Abusive Supervision

Leaders experience a double whammy when they’re sleep deprived. Not only are they as prone to higher perceived work stress but their supervisory behaviour takes a hit as well. Previous research has shown that missing a single night of sleep saps executive function, which is in charge of self control, cognition, emotions, and behaviour. Getting only five hours of sleep a night, for four nights in a row, leads to the same cognitive deficits caused by a blood alcohol level of 0.6 percent (three drinks for men; two for women).

Carleton decided to see if the dip in self control caused by a single night of bad sleep could affect leaders’ behaviour. Over 15 days, Carleton monitored the indirect effect of a leader’s quantity and quality of sleep on their transformational leadership and abusive supervision, as rated by their direct reports. While the study failed to capture an impact on transformational leadership, a lack of sleep led to a rise in abusive supervision, through sleeps effects on self-control, even after a single night of unsatisfying sleep.

Carleton still suspects that sleep is linked to transformational leadership. “I really think it’s a different mechanism, not self control, that leads to a change in positive behaviour,” says Carleton, who plans to pursue the link in further research. “When you sleep well, you obviously do demonstrate positive behaviour, but what’s the mechanism behind that?”

Sleep and Work Withdrawal

One link Carleton did uncover, however, was the connection between lack of sleep and work withdrawal behaviours such as partial absenteeism (at work but not working), absenteeism, and work neglect.

Carleton’s third study examined how sleep was linked to these irritating and costly behaviours. Between 35 and 40 percent of adult Americans struggle with either daytime sleepiness or falling asleep on a daily basis. For some, it’s a chronic problem. To dive deeper, Carleton chose to study individuals with obstructive sleep apnea, a clinical sleep disorder that affects one in four Canadian adults, both before and after treatment.

Those with sleep apnea can be roused from sleep five to 30 times an hour, and often find themselves extremely sleepy the following day. Carleton found that the daytime sleepiness caused by sleep apnea led employees to skip work, arrive early or leave late, take more breaks, and neglect their work. When they were treated for the condition, their daytime sleepiness — and, subsequently, work withdrawal behaviour — decreased over time.

And it’s not limited to those with sleep apnea: “Other research demonstrates that daytime sleepiness has effects on withdrawal behaviours in the general population, too,” says Carleton. By being able to examine those with sleep apnea, however, she was able to examine a direct change: how healthier sleep patterns lead to less withdrawal at work.

Working Around Sleep Deficits

Being aware of the potential effects of sleep deficits can help us as leaders, supervisors, and individuals.

“I think we sometimes tend to label people as something or not something — as in, that leader is or isn’t abusive — but my research demonstrates that’s not the case,” Carleton says. “It’s a matter of their situation, in terms of how tired they are.”

She acknowledges that there will be times in which leaders cannot get sufficient sleep. When those days hit, she suggests scheduling tough conversations or pressing matters early on in the day, when they are most alert and have more control over themselves. “Just knowing the effect sleep has on abusive behaviour might make leaders more cognizant of how they’re actually treating their employees across different days.”

As an individual, be aware of your own limits, shut off your phone when you need rest, and recognize that to do your best work, you need to be running on enough sleep.

“How we culturally think about sleep is something that needs to be addressed and changed within the workplace,” says Carleton. “We’re not doing ourselves any favours by staying at work for 15 hours a day, because your work is not going to be good.”

Kenza Moller

Smith School of Business
Goodes Hall, Queen's University
Kingston, Ontario
Canada K7L 3N6

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