First, congratulations! You just made a decision: to click on this blog post. That choice likely happened subconsciously. Maybe the headline caught your attention, or perhaps curiosity led you here. Either way, your brain may have made the decision before you even realized it. And it doesn’t stop there. Think about your current posture, your last meal, or what you’re wearing today. Each of these is the result of a decision. Sometimes active, sometimes passive, but most often subconscious. But have you ever made the decisions to think about how decisions are made? If not, here’s your chance.

Our brain is an incredibly efficient processor, often compared to a computer’s processing unit. Both handle vast amounts of information with remarkable performance. However, despite its complexity, the human brain likely consumes far less energy than a conventional computer (there are reports that the brain takes only 20 watts of power). Unlike computers, where every process can theoretically be understood, the brain remains largely a mystery. While we have insights into brain regions, their connections, and communication pathways, the exact mechanisms behind real-world problem-solving are still not fully understood. Decision-making is one of the brain’s core functions, extending far beyond simple A-or-B choices. Before making a decision, we first need to recognize something as a problem, determine a desired outcome, and evaluate potential solutions. Remarkably, most of these steps happen almost instantaneously! Studies suggests that we make around 30,000–35,000 decisions per day, and more than 200 of them are solely related to your meal. Yet, the majority of these decisions occur subconsciously, without us even realizing it.

Complex brain for intuitive decisions?

A decision can be understood as the selection of the best option from a choice set containing two or more alternatives (Beach., 1993), motivated by overarching goals. However, not all decisions follow strict logic or deep reasoning. Instead, behaviour and choices often rely on heuristics, which are mental shortcuts, conscious or unconscious, that provide solutions that are good enough (Gigerenzer et al., 2011). Heuristic reasoning typically comes into play when individuals must act quickly or navigate multiple competing goals (Gigerenzer, 2008). There are multiple heuristics, one well-known example being the availability heuristic. This heuristic is often applied unconsciously when humans need to assess the importance or frequency of an event under time pressure or when precise statistical data is unavailable. In such cases, judgments are influenced by how easily similar events come to mind. Events that are more readily recalled tend to be perceived as more probable than those that are harder to remember. The problem is that outcomes potentially leading to biased or incorrect conclusions. While heuristics can be efficient in everyday decision-making, they may pose significant risks in safety-critical environments such as aviation. In such contexts, reliance on heuristic decision-making can lead to bad decisions with potentially severe consequences.

Option A or B or something else?

Some decisions are easy and made quickly (do I take a spoon or a fork for the soup?). Others require a bit more thought (am I in the mood for pasta or a salad?). And then there are decisions that are trickier. What happens when a situation doesn’t present a clear right or wrong choice, but rather, each option comes with its own advantages and disadvantages? If you’re under time pressure to make the best possible decision, the challenge quickly escalates into a stressful task. In aviation, such situations can arise rapidly, with safety always being the primary concern.

Let’s consider a fictional emergency scenario: You’re a pilot flying over the Atlantic when you receive a report that a passenger is showing symptoms of a heart attack and requires urgent medical attention. Your onboard resources are limited, so landing as soon as possible is crucial. Your planned destination is still hours away. There is an alternate airport just a few minutes away, but the weather report warns of strong winds and heavy snow, making the landing potentially hazardous. A third airport is slightly farther away, with good weather conditions but limited medical infrastructure, posing a risk to the patient’s health. Ask yourself, how would you decide?

Of course, this is a hypothetical example, but it illustrates the complexity and ambiguity of decision-making in aviation. Pilots operate in teams, and no critical decision should be made without consulting the other pilot. This principle is central to Crew Resource Management (CRM), which focuses on optimizing available resources to enhance safety. CRM includes cross-monitoring, mutual support, effective communication, task delegation, and joint decision-making. To structure and formalize decision-making, especially in critical situations, models such as FORDEC have been developed. This acronym represents a structured approach to decision-making:

• Facts: Identify and list the key facts of the situation. What is the nature of the emergency?
• Options: Evaluate the possible courses of action. What choices are available?
• Risk and Benefits: Assess the risks and benefits of each option. What are the pros and cons of flying to Airport A versus Airport B?
• Decision: Make an active and informed decision based on the analysis.
• Execution: Implement the chosen course of action.
• Check: Monitor the outcome: Does the decision work as intended? If the situation changes, should the plan be adjusted?

By following structured decision-making models like FORDEC, pilots can ensure that even under pressure, decisions are made systematically, with safety as the top priority. FORDEC can be applied in different ways. In non-time-critical situations, the entire FORDEC process can be followed step by step to identify the best possible solution. However, in time-critical situations, FORDEC can help to quickly identify the first suitable solution. Structured decision-making significantly improves outcomes and decision quality by reducing the influence of heuristics, biases, and other cognitive traps.

Given the immense processing power of our brain, it almost seems paradoxical that heuristics and biases exist. Don’t they limit our decision-making performance? Or is it rather the other way around? Perhaps we owe our high cognitive efficiency to heuristics, as they allow us to process information rapidly and effectively.

References 

Gigerenzer, G. (2008). Why heuristics work. Perspectives on psychological science, 3(1), 20-29.

Gigerenzer, G., & Gaissmaier, W. (2011). Heuristic decision making. Annual review of psychology, 62(2011), 451-482.

Beach, L. R. (1993). Broadening the Definition of Decision Making: The Role of Prechoice Screening of Options. Psychological Science, 4(4), 215-220. https://doi.org/10.1111/j.1467-9280.1993.tb00264.x 

Safety is always expected when flying, but rarely considered by passengers. It is something everybody wants, yet no one can fully guarantee. The aviation industry works extensively to enhance safety, and today, the chance of being involved in a fatal aircraft accident (per flight hour) is 0.000000001. In other words, the likelihood of a catastrophic aircraft failure is just one in a billion flight hours. To put this into perspective, the odds of being struck by lightning in a given year are less than one in a million.

We dream of a world without accidents, incidents, or any kind of trouble – and that is fully understandable. Any aircraft disaster that results in loss of life is tragic and should never happen. But if we take a moment to reflect, how far have we actually come? In the course of the development of modern aviation over the last 100 years, there have been numerous near misses and tragic accidents. Initially, it was mainly technical faults, but later humans were also identified as a contributory factor – the birth of human factors research. Mankind desperately wanted to fly, reliably and safely. Thus, the aviation industry managed to understand the “why” behind many accidents, improving technical and human reliability. But was all this necessary? Could it be that a certain degree of un-safety was or is necessary to achieve greater safety?

Let’s go out on a hike

Imagine you are hiking on a well-marked mountain trail. The path is clear, the weather is perfect, and you are feeling confident. To add a little excitement, you decide to step off the trail now and then, maybe to snap a photo of a beautiful wildflower. At first, it seems harmless. The trail is still in sight, and you are only a few steps away. But as you keep hiking, these small detours become a habit. Each time, you wander slightly farther from the trail. A few more feet to explore a rocky spot. The terrain starts to look rougher, but you don’t panic. After all, you are still close enough to hear other hikers, and the trail is just over there. After some time, the sky clouds over. The trail makers become harder to spot. Oh no! You suddenly realize, you are standing in the thicket of bushes. And which direction should you go to come back? The phones battery drained out and no trail is in sight. What began as tiny, reasonable risks has left you stranded in a dangerous situation.

We can try to transfer that example to socio-technical systems and aviation. Rasmussen’s drift-to-danger model (1997) describes how human behavior and decision-making in safety-critical industries fluctuate within certain boundaries. Decisions and actions of systems and operators are based on several factors. There are safety margins, which influence behavior. But other pressures are there as well. Management often pushes for increased efficiency, placing pressure on workers to maximize output (economic failure boundary), while individuals may also be motivated by the principle of minimum effort (unacceptable workload boundary). That does not mean that people are lazy. Let us say humans want to work as efficiently as possible. Work overload is something to be avoided. And the model postulates that as long as we stay within these boundaries, we are safe. But what if we stretch these boundaries? And what if we even overstretch the boundaries? As a result, there is usually a drift towards the third boundary: the functionally acceptable performance. In other words: safety. If this boundary is breached, safety can be compromised.

When being on a hike and making detour, this describes the stretch. It describes the drift to danger:

1. Small, seemingly safe decisions: Each detour felt minor. You just step off for a second.
2. No immediate consequences: Nothing bad happened at first. You kept pushing the boundaries.
3. Crisis sneaks up: By the time you realized the danger (got lost, bad weather), it was already too late.

Back into the bushes. After a while, a ranger comes into view. She tells you that this often happens and that she makes extra rounds through the countryside to look for stranded hikers. Together you find your way back to the path.

So, what does this mean for aviation and safe systems? To put it briefly: we need a resilient system. Resilience is a measure of a system’s ability to absorb continuous and unpredictable change and still maintain its vital functions (Pregenzer, 2011). In this context, resilience is the ability of an organization and a system to anticipate when these safety limits are in danger of being exceeded and to take countermeasures. Resilient systems are characterized by a heightened awareness of unexpected situations and the ability to develop strategies to mitigate them (Hollnagel, Woods, & Leveson, 2006).

That was close

After a few days of reflection, you understand what caused you to get stranded. You realize how dangerous it was. And you decide that you won’t do it again. Next time you’ll stay on the path, that’s the lesson you’ve learned. But would you have been able to recognize that without the event?

Many accidents cannot be predicted due to the high complexity of systems and unforeseen system states. Ironically, it is often these very accidents that reveal a systems weakness. Do we then have to live with accidents to discover the weaknesses? Well, yes and no. Probably we cannot avoid every accident. But we can do something proactive. Accidents rarely happen without warning. There are usually precursors: unusual system states, error messages, minor incidents or even bad feelings of the human. Those signal potential system issues and perhaps even predict incidents. Thus, it is crucial for organizations to recognize and investigate these warning signs. This responsibility typically falls to the safety department, which carefully analyses incidents and even the slightest deviations to identify risks before they escalate. With that, resilient systems can be shaped.

All of this goes unnoticed by passengers, but safety should never be taken for granted. The next time there is a delay due to a technical check or a procedural disruption, remember that these measures are taken for safety. Every precaution, no matter how small, is part of a system designed to prevent accidents before they happen. And remember, in aviation, these measures are often the result of incidents or even accidents.

References 

Gigerenzer, G. (2008). Why heuristics work. Perspectives on psychological science, 3(1), 20-29.

Gigerenzer, G., & Gaissmaier, W. (2011). Heuristic decision making. Annual review of psychology, 62(2011), 451-482.

Beach, L. R. (1993). Broadening the Definition of Decision Making: The Role of Prechoice Screening of Options. Psychological Science, 4(4), 215-220. https://doi.org/10.1111/j.1467-9280.1993.tb00264.x 

Twinkle, twinkle, lite star… No, wait… not now! It is 3 AM, my coffee is gone cold, and my brain feels like static – welcome to the night shift grind!

Our modern society requires people to work at inconvenient times. Early in the morning, late in the evening or throughout the night. But there is no other choice: air traffic has to be monitored at night, and if an early departure is scheduled, pilots have to check in at 4 a.m. to prepare the airplane.

Working at night is risky. That is more or less cold coffee now. But are all shifts similarly demanding? And what can be done? We will explore night work and talk about strategies. And why kiwi fruit may be more relevant than you think.

We are Owls or Larks (or something in between)

Humans are biphasic. We either are awake or sleep. During a 24-hour cycle we require a distinct sleep when not being in wake phase. The timing of the sleep phase seems to matter as well. In research, there is common understanding that work during the night time seems to be associated with risks.

A night shift cannot be viewed separately. It must be portrait in regards to many other aspects, such as sleep during the last days, physical activity and chronotype. During a given night shift, sleepiness and fatigue can be also product of our inner circadian rhythm. The circadian rhythm is our inner clock that drives many of our physiological processes. That includes the release of hormones, onset of sleepiness and sleep. Two distinct biological processes interact to regulate sleep and wakefulness: Process S and Process C (Borbély, 1982). Process S (red line in graph below) is like a “fatigue tank” in your body. The longer you are awake during the day, the more this tank fills up – you become sleepy. At night, while you sleep, the tank empties again. This refers to the sleep-wake homeostasis, representing the physiological drive for sleep, which accumulates during wakefulness and dissipates during sleep. Process C (blue line in graph below) is your internal clock, which ticks independently of the pressure of sleep. It tells you in the evening: “Time to sleep!”, even if your “fatigue tank” is not full. It wakes you up in the morning, even if the tank is not yet completely empty. This refers to the circadian rhythm, which governs the timing of sleepiness and wakefulness over a 24-hour cycle, independent of sleep debt.

Both processes interact with each other. During the day, Process C keeps you awake, even when sleep pressure (S) rises. In the evening, Process C triggers the need for sleep, while Process S empties the “tank”. Problems such as jet lag arise when the internal clock (C) does not adjust quickly. Sleep deprivation occurs when the “tank” (S) is not emptied enough.

And what is the deal with owls and larks? This refers to our chronotype, i.e. our body’s natural tendency to be asleep or awake at a certain time. In other words, it is the behavioural manifestation of the underlying circadian rhythm. You may have met people who like to get up early in the morning and go to bed early at night – congratulations, you have just met a lark (or rather a person with a morning chronotype)! And then, of course, there are those who like to get up late in the morning after going to bed late at night. These are the owls, that means people with an evening chronotype. Perhaps you see yourself somewhere in between. But that is fairly normal as most people are actually intermediate chronotypes, falling into a category somewhere in between.

Are All (Night) Shifts Equally Challenging?

Let’s be clear: The human is not made for night work. Night shifts are and will always be a challenge that is associated with risks. Shift and (night) work is inherently associated with an increased risk to physical and mental health, reduced safety, a poorer social life and lower work performance. So, are all night shifts equally demanding? No, of course not. A lot depends on your genetic predispositions, your sleep and your work experience. The shift schedules you work play an important role. Rotating shifts disrupt the circadian rhythm much more than fixed shifts (Folkard & Tucker, 2003). Individual differences between us moderate tolerance to shift work and night shifts. Personality and some genetic predispositions have been found to be related to higher tolerance to shift work (Saksvik et al., 2011).

Survival Strategies: What Actually Works?

According to most researchers, the most effective strategy for overcoming the negative effects of night shifts is a nap. Napping refers to short sleep opportunities of 20 to 40 minutes. It seems to be optimal if the napping episodes are scheduled during the work shift, e.g. with the help of napping programs (Ruggiero et al., 2013). If night work is considered in a broader context, the influence of (day) light should be taken into account. The circadian rhythm synchronizes with daylight. Night shifts disrupt it, but it is possible to adapt: If night work is planned, the circadian rhythm can be adjusted. Remember that your body clock is stubborn – it changes very slowly (think days or weeks, not hours). Thus, light as intervention needs to be used very strategically.

And what is with the Kiwi?

From a night worker’s perspective, kiwi fruit can be a superfood! Kiwis are rich in serotonin and antioxidants, which have been linked to improved sleep quality. But that’s not all. One study found that eating kiwifruit improved the onset and duration of sleep (Lin et al., 2011). So why not consider a kiwi snack before your next sleep episode? Of course, there are many aspects to consider when working shifts, and eating just one kiwi a day is unlikely to help and solve the challenges entirely.

But next time you are staring at the 3 AM void, remember: science can help to save your shift (and to make another fresh coffee).

References 

Gigerenzer, G. (2008). Why heuristics work. Perspectives on psychological science, 3(1), 20-29.

Gigerenzer, G., & Gaissmaier, W. (2011). Heuristic decision making. Annual review of psychology, 62(2011), 451-482.

Beach, L. R. (1993). Broadening the Definition of Decision Making: The Role of Prechoice Screening of Options. Psychological Science, 4(4), 215-220. https://doi.org/10.1111/j.1467-9280.1993.tb00264.x