Employee Sleepiness is Harmful for the Workplace

Topic(s): Health & Safety, job performance, wellness
Publication: Journal of Applied Psychology
Article: Sleepiness at Work: A Review and Framework of How the Physiology of Sleepiness Impacts the Workplace
Authors: H.M. Mullins, J.M. Cortina, C.L. Drake, R.S. Dalal
Reviewed by: Ben Sher

Sleepiness is what happens when people feel a strong biological urge to sleep. Unlike fatigue, which usually occurs when becoming exhausted by hard work, sleepiness has several different causes. These causes include poor sleep quantity (not getting enough sleep), poor sleep quality (waking up often while trying to sleep or not achieving a deep level of sleep), a disruption to the circadian rhythm (a person’s natural sleep cycle), or through drugs or disorders that affect the central nervous system. A new review (Mullins, Cortina, Drake, & Dalal, 2014) shows why organizations should care about employee sleepiness.


The authors mention two major work-related factors that can eventually lead to sleepiness for employees. Job demands are elements of the job that require effort. When these job demands are excessively high, employees may experience reduced quality of sleep and reduced quantity of sleep. For example, employees may be under enormous pressure to make a deadline or to complete a project. This might lead employees to work later and have less time for sleep, or to have trouble falling asleep or staying asleep.

The second major work-related factor that can lead to sleepiness is irregular work-schedules. We would probably consider a normal work-schedule to be “nine-to-five” for five days a week, or something similar. But some employees work nights, weekends, or long shifts that may last 24 hours at a time. These schedules can wreak havoc on the body’s circadian rhythm, or natural sleep cycle. This can cause employees to receive an inadequate amount of sleep or an inadequate quality of sleep.


Employees who experience sleepiness experience two major physiological changes. They become worse at information processing, and their feelings are affected. Information processing is the “brain power” that employees need to get their jobs done. When sleepiness occurs, people can’t think as fast, can’t remember as well, can’t learn as effectively, and can’t pay attention as long. In regards to feelings, employees who are experiencing sleepiness will experience less positive emotion and more negative emotion. Additionally, they will have poor emotion recognition and processing, meaning they might incorrectly interpret the mood of a fellow employee or fail to handle an emotional situation sensitively and tactfully. It is easy to see how these deficiencies can cause negative outcomes at work.


The authors note several examples of research-supported outcomes of workplace sleepiness. First, sleepy workers are less productive. They react more slowly, make more mistakes, and forget to do things. Second, sleepy employees have worse adaptive performance. This means that they will not be able to figure out how to handle changing situations and novel challenges, things which are becoming increasingly common in the modern workplace. Additionally, they will have trouble multi-tasking or quickly switching between different tasks, also common elements of the modern workplace.

Next, sleepy workers have worse contextual performance. Contextual behavior is anything done to help improve the work environment, and can include praiseworthy interpersonal behavior or simply going above and beyond job requirements. When employees are suffering from sleepiness, they are more likely to mismanage or misinterpret an interpersonal exchange, which can lead to poor communication or arguments. Also, sleepy employees tend to experience a greater range of feelings, including exposure to more negative feelings. It’s easy to see why someone in that state will have trouble contributing to the work environment in a positive, healthy manner.

Finally, sleepy employees are more accident prone, engage in more deviant behavior such as absenteeism, and exhibit more withdrawal behavior, which is when employees try to avoid things that they consider unpleasant. These too have the potential to greatly impact workplaces and organizations in a negative way.


Employee sleepiness is highly detrimental in the workplace. But how can organizations prevent it? One strength of this article is that the researchers identified several things that can eventually lead to sleepiness, including job demands and irregular work schedules. Asking employees to take on an increasingly heavier workload may seem to have short-term benefits for the organization. However, if employees experience sleepiness as a result, the ultimate effect could be negative for the employees and the organization. Similarly, organizations who are forced to use shift work or other irregular schedules should seek out ways to ensure that scheduling allows employees to maximize their ability to get adequate sleep.


Mullins, H. M., Cortina, J. M., Drake, C. L., & Dalal, R. S. (2014). Sleepiness at work: A review and framework of how the physiology of sleepiness impacts the workplace. Journal of Applied Psychology, 99(6), 1096–1112.