How would you describe your mood when you don’t get enough sleep? Let’s say you only slept three hours because you were up late with sick kids, working on a report for work, or simply binge watching your favorite show. How cheerful or positive would you feel the next morning? My bet is that you might not be very fun to work with on that particular morning!It’s no secret that people generally feel more grumpy, irritable, and impatient when they sleep poorly. This has been well documented by researchers before – there is a very strong and consistent link between sleep and mood. In laboratory studies where people are subjected to systematic sleep loss (sounds like a fun, doesn’t it?), results consistently show that most individuals experience increases in negative mood, irritability, and even feelings of depression. That’s because we need our sleep not only for physical health, but also our mental and emotional well-being.
As I mentioned in the first part of this blog, the National Safety Council (NSC) just shared the results from their study, finding the immense safety risks and costs that are associated with fatigue1. I also discussed that due to genetic physical and psychological differences, some people are more vulnerable to the effects of sleep loss, which can put them at higher risk of injury on the job when they are tired. Those interpersonal differences are highly related to mental abilities such as attention, decision making, and problem solving, which are all part of the SafetyDNA® factor, Awareness.
Emotional Control – An Important Personality Trait for Safety
Awareness is not the only SafetyDNA factor that influences how we are affected by sleep loss. There is another critical trait that is directly linked to our mood, emotional stability. This is one of the “Big 5” factors of personality that is often studied in workplace settings2. It is a well-established personality factor in psychology that can be described as your general level of calmness, self-control, confidence, and ability to effectively regulate stress and emotions. People who score higher on this trait tend to be less impulsive and have less general anxiety and fewer mood swings compared to those who score lower on this trait. Studies have found that people who have higher emotional stability tend to have more success on the job, better job satisfaction, and are less likely to quit their jobs (Barrick, Mount & Judge, 2001; Zimmerman, 2008).3,4
From a safety perspective, it's interesting to note that studies have found a link between emotional stability and workplace injuries5. In other words, individuals with less emotional control tend to engage in more risky behaviors and have more workplace injuries compared to those with higher levels of control. Given all of the previously mentioned research findings, it’s no surprise that those with lower levels of emotional stability or control are at greater risk of injury. They are more likely to make impulsive decisions without thinking things through and are more likely to experience prolonged stress and anxiety at work, which can increase our risk of injury at work. That’s precisely why “Control” is also one of the four factors in the SafetyDNA model.
When we are stressed out or highly agitated about something (problems at home, arguments, faulty equipment that keeps breaking down), we can get distracted from what we are doing on the job. The same goes for being impulsive – when we make quick decisions in-the-moment without thinking of potential consequences, bad things can happen. When was the last time you made a GREAT decision when you were extremely upset? In those moments, we often do things that we later regret. It’s obvious that when we are in these types of mindsets, they can cloud our judgment and lead us to make poor decisions – especially when we are surrounded by potential work hazards that can injure or kill us.
So, here's the bottom line:
We all have a different levels of emotional control that help define our stable personality – some of us “lose it” much faster and more often than others (agitation, stress, anxiety, etc.).
People with lower levels of emotional control tend to have a higher risk of injury on the job.
The Connection Between Control, Fatigue, and Injury Risk
Where does fatigue fit into all of this? Well, it turns out that our emotional control levels are strong predictors of our sleep habits and sleep quality. Studies have shown that individuals with low control tend to sleep more poorly than others. Specifically, they tend to engage in behaviors that lead to poor sleep, they report much lower sleep quality, and they experience significantly more sleepiness throughout the day. These findings take into account various other characteristics such as age, gender and even socioeconomic status. None of these factors predicted overall sleep as well as their emotional stability scores in this study6. Similar results have been found in other settings and demographic groups.7
It’s not hard to imagine that if a person is more likely to be stressed out, anxious, angry, or frustrated, it could lead to less sleep or lower quality sleep. The result? That person is much more likely to be consistently fatigued on the job compared to someone whose personality profile is less likely to experience these mental states. And, since other studies have found that emotional control is linked to greater injury risk regardless of sleep, in essence, this results in a “double whammy” effect for certain individuals. In other words, people who are lower on this trait have a greater risk of injury on the job for two distinct reasons: they are more likely to make unsafe decisions at work due to frustration and poor stress, and they are also more likely to be fatigued on the job due to sleep deprivation.
Knowing is Half the Battle
This is why it is important to take into account differences in characteristics such as personality traits. If you knew you were at elevated risk of a heart attack due to blood pressure or high cholesterol, would you do something about it? Would you consider that information to be valuable? Why should our personal safety be any different? If we could reduce our likelihood of injury or death on the job during hazardous tasks by just 10% by knowing certain aspects of our personality profile and our tendencies, why not take advantage of that information in order to further reduce our risk? If safety is the most important value in our organization, perhaps we should use all of the information that is available to us in order to help people be better equipped to work safely by accounting for the different ways in which we all handle the risks of fatigue on the job. Through the use of validated, technically sound psychological tests, these important traits can be reliably measured, allowing us to use the resulting information for valuable coaching, feedback and behavioral change efforts that are customized to each person’s unique SafetyDNA traits.
Fatigue in safety-critical industries: Impact, risks & recommendations. National Safety Council, 2017.
Barrick, M.R. & Mount, M.K. The big five personality dimensions and job performance: A meta-analysis. Personnel Psychology, 44, 1-26.
Barrick, M.R., Mount, M.K & Judge, T.A. (2001). The FFM personality dimensions and job performance: Mega-analysis of meta-analyses. International Journal of Selection and Assessment, 9, 9-30.
Zimmerman, R.D. (2008). Understanding the impact of personality traits on individuals’ turnover decisions: A meta-analytic path model. Personnel Psychology, 61, 309-348.
Beus, J.M., Dhanani, L.Y. & McCord, M.A. (2015). A meta-analysis of personality and workplace safety: Addressing unanswered questions. Journal of Applied Psychology, 100, 481-498.