Three safety professionals were asked to evaluate their company’s previous year’s 129 incident investigation reports to determine what could possibly be done to reduce both the number and severity of injuries. Although they collaborated on the evaluation, each presented their course of action to the vice president of safety, health and environment separately. There was slight variation among the three approaches, but generally they were the same. The three presentations were made over the course of several days.

Safety Pro 1 (Presented at 8:30 AM): Proposed revising certain procedures relating to the most severe injuries and increasing management safety observations.

Safety Pro 2 (Presented at 3:00 PM): Proposed strong emphasis on safety from senior leadership down through directors and increasing the number of safety audits.

Safety Pro 3 (Presented at 4:30 PM): Proposed operational supervisors start conducting safety observations of their crews and eliminating safety requirements that did not make any sense in the current state of the organization.

So which safety pro do you think won approval to go forward with his approach?

Decision fatigue

According to Roy Baumeister, professor of psychology at Florida State University, and John Tierney, New York Times science columnist, the odds favored the vice president selecting the safety pro who presented his approach at 8:30 AM.

Why? Emerging research that Baumeister and Tierney explore in their new book Willpower – Rediscovering the Greatest Human Strength1  is beginning to reveal that making decisions throughout the day wears us down mentally. 

We are all familiar with physical and mental fatigue. Virtually none of us are aware of decision fatigue even though we experience it often ourselves or observe it in others practically every day. 

Examples Baumeister and Tierney offer include when quarterbacks make dubious decisions late in the game, or when reasonable people get angry at colleagues late in the afternoon and family members in the early evening hours, splurge on clothes, buy junk food at the checkout in grocery stores, or cannot resist a car salesman’s offer to rustproof a new car. 

When individuals are asked if making decisions depletes their willpower and makes them vulnerable to temptation, most people say no.2   Decision fatigue influences everyone every day, some to the point of career disasters.

Sapping mental energy

As the authors note, there is a biological price to be paid regardless of how rational you may be when making decisions all day long. The more decisions you make during the day, the harder each one becomes, resulting in the sapping of your mental energy or willpower.

The nexus between willpower and decision-making cuts both ways. As you make more and more decisions during the day, your willpower is depleted, and as your willpower depletes, you are less inclined to make decisions.3 If your job involves a number of decisions to be made all day long, eventually mental energy will be depleted to the point that you will seek the path of least resistance and either make bad or reckless decisions or opt to make no decisions.

Where does the power in willpower come from? Matthew Gailliot, a Baumeister graduate student, started to answer the question by testing the Mardi Gras Theory (i.e., building up willpower by first indulging yourself in pleasure) through consuming copious calories the day before Lent; however, he discovered it did not matter if the calories came from alcohol consumption, eating King Cake, beignets, and other rich foods, or drinking a tasteless concoction of low-fat dairy glop. The calories were converted to glucose, the simple sugar manufactured in the body from all kinds of foods, not just sweet ones.4

The glucose connection

Baumeister and Tierney explain the connection between glucose levels in our body and our ability to exercise self-control. As glucose levels decline during the day, the power in our willpower declines also. The extreme of this low-blood sugar condition is found in diabetics. Researchers have found diabetics tend to be more impulsive and have more explosive temperaments than other people their age. Diabetics are easily distracted when doing time-consuming tasks. Hence the reason diabetics must monitor their blood sugar closely in order to maintain their health and self-control.5

So when does decision fatigue set in?

Kathleen Vohs, a former colleague of Baumeister, conducted an experiment to demonstrate what psychologists call the “Crossing the Rubicon Model” of action phases — “predecisional phase” and “postdecisional phase”— in other words, the act of passing a critical point of no return.

Dr. Vohs utilized the self-service sales site of Dell Computer Company. Three groups were randomly selected. Group one was asked to look at features of a computer, think about options and prices, advantages and disadvantages, form a preference, but not make a definite selection— the “Predecisional Phase.” Group two was given a list of computer specifications and told to configure a computer. They had to locate the specified features online and click the right one — the “Postdecisional Phase.” Group three was told to choose on their own the features they wanted on their customized computer. This group did more than ponder options or implement someone else’s choices. They actually had to “cross the Rubicon” and make specific decisions to build their customized computer. The experiment revealed that the third group’s task was most fatiguing. When Vohs measured self-control, group three was far more depleted than the other groups.6

The safety connection

How does decision fatigue relate to safety?

Since we all suffer from decision fatigue, it would seem obvious that individuals who are involved in making safety decisions during their daily work routine might have a tendency to either make careless decisions, no decisions, or take the path of least resistance in the later afternoon hours or toward the last hours of their shift.

Here is a hypothesis safety professionals could test. Retrieve the past 50 to 100 accident reports your organization has investigated and compare the time of the day the accident occurred to the severity of the injury(s). Did most of the accidents occur in the afternoon or during the closing hours of the employee’s shift? Did the severity of the injury increase toward the end of the day or shift?

Over the course of my career, I have often heard the excuse for an accident occurring and an employee sustaining an injury was due to the employee’s habit of cutting corners or simply disregarding the safety rules because they got in the way of getting the job done. This could very well be the case, but it appears now that the employee could have been a victim of decision fatigue.  

Fighting the fatigue factor

To counteract decision fatigue, consideration should be given to the following:

• When scheduling complex maintenance activities, consider beginning the work early in the morning or the shift rather than late in the afternoon or during the waning hours of a shift.

• If you need a decision from your boss, don’t schedule your conversation in the afternoon hours. Meet with your boss in the early to mid-morning hours.

• Increase your knowledge and application of behavioral monitoring or living and working by the numbers, your numbers. Research has shown that monitoring one’s own behavior will lead to a higher level of self-awareness, which in turn leads to greater self-control and stronger willpower.  

Traditionally, people have monitored their behavior in notebooks or on pieces of paper.  Learn how to live by your own numbers at such websites as: (to improve your productivity), (to improve the management of your money), (to track the music you listen to and receive suggestions of similar genre music), (a Mac application to track attention and usage data while you are on your Mac), and (to track your body weight and blood pressure on your iPhone or Android device and automatically send it to your doctor), just to name a few behavior monitoring tools. 

As safety professionals, we spend vast amounts of our time trying to change peoples’ safety behavior. Since behavioral monitoring tools and applications have certainly evolved, rather than focusing solely on safety behavior, maybe it is time to encourage people to monitor their own behavior for those areas they want to improve. Once they experience success, self-esteem will likely rise leading to personal reasons for wanting to work safely.