Better sleep can lead to strengthened relationships among colleagues.

Harvard Business Review | Cristiano Guarana & Christopher M. Barnes | Research: Sleep Deprivation Can Make It Harder to Stay Calm at Work

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When new managers and their employees meet for the first time, they begin to forge their working relationship, which will be a crucial factor in how they both experience work, how much they trust each other, and how effectively they can work together. You may have a direct report that you hold in high regard, whom you give the most important tasks to, and spend the most time mentoring. You may have another direct report whom you see as a drag on the team, give fewer opportunities to, and are less effective working with. The first few months of working together with any given employee is especially important in determining how the relationship will proceed.

In this post, we discuss a newly uncovered predictor of the quality of these relationships: sleep. In our previous work, we found that sleep deprivation undermines leader charisma and can lead to abusive supervisor behavior. Building in part from that work, in our latest project we sought to examine how sleep influences the development of leader-follower working relationship quality in newly assigned leader-follower pairings. We start from the premise that sleep deprivation would make leaders and followers experience more negative emotions at work (in the form of hostility). You can probably easily remember a time in which you had a short night of sleep and had a bit of a short temper at work the next day. This is a very common experience, and is largely driven by the fact that sleep deprivation undermines the parts of your brain involved in regulating emotions.

The expression of hostility can be damaging to a newly forming work relationship. Hostility naturally invokes feelings of threat, and erodes feelings of psychological safety in a given context. A single episode of yelling hostilely at a an employee might be forgiven. However, if it is a common occurrence, that employee may start to feel that the supervisor has a lack of respect and empathy, and that they have a poor quality work relationship with that leader. Indeed, there is previous research indicating that the expression of hostility is damaging to relationships. Thus, our prediction was that sleep deprivation would lead to the expression of hostility, which would in turn damage the working relationship between a manager and an employee.

In testing these predictions, we examined both sides of the leadership coin: leaders and followers. We conducted two field studies with newly assigned leader-follower pairs in organizations situated in Brazil. In our first study, 86 leader-follower pairs that had just started working together completed a survey about their sleep, hostility, relationship quality, and other variables that were used as statistical controls. Consistent with our expectation, we found that leader sleep deprivation undermined the follower’s perception of the quality of their working relationship. We also found that the effect went the other way as well; sleep deprivation on the part of the follower also had a harmful effect on the leader’s perception of the quality of their work relationship.

With this initial set of results supporting our hypotheses, we sought to replicate the results with a longitudinal study in which we asked leaders and followers to fill out a series of surveys over three months. This second study mainly replicated our findings of the first study, but we were also able to test whether the relationship between sleep and relationship quality varied over time. Once again, we found that sleep deprivation on the part of either party was harmful to the relationship quality perception of the other party. We also found that sleep deprivation of leaders was unrelated to their own perceptions of their relationship quality with their followers (and vice versa for followers). In other words, sleep deprived leaders were unaware that their sleep deprivation was harming their working relationship with their employees. Much like a person who has had a little too much to drink and does not realize they will be impaired when driving, sleep deprived leaders are essentially clueless about how their sleep deprivation leads their employees to mistrust and dislike them. 

This has important practical implications for managers. Your relationships with your direct reports are some of the most precious resources you have. You can ask more of, get more out of, and more effectively work with employees who trust, like, and respect you. Undermining these precious relationship resources, especially when doing so unknowingly, is a sure way to sabotage yourself and your team. You should instead seek to protect and grow these relationships through as many different avenues as you can. Looking after the development of your team members, treating them with respect and care, and working with integrity are some of the ways you should already be trying to foster these relationships. Our research indicates that an additionally important way to develop and maintain positive work relationships is to get a good night of sleep. It may be tempting to trade away more and more of your sleep in order to squeeze in more work time, but doing so can sabotage your own odds of success in the future.