Human nature encompasses all the physical, biological, social, mental, and emotional characteristics that define human tendencies, abilities, and limitations. One of the innate characteristics of human nature is imprecision. Unlike a precise machine—each time, every time—people are imprecise, especially in certain situations. For instance, humans tend to perform poorly under high stress and time pressure. Because of “fallibility,” human beings are vulnerable to external conditions that cause them to exceed the limitations of human nature. Vulnerability to such conditions makes people susceptible to error. Susceptibility to error is augmented when people work within complex systems (hardware or administrative) that have concealed weaknesses—latent conditions that either provoke error or weaken controls against the consequences of error.
Common Traps of Human Nature
People tend to overestimate their ability to maintain control when doing work. Maintaining control means that everything happens that is supposed to happen during the performance of a task and nothing else. There are two reasons for this overestimation of ability.
First, consequential error is rare. Most of the time, when errors occur, little or nothing happens. So, people reason that errors will be caught or won’t be consequential.
Second, there is a general lack of appreciation of the limits of human capabilities. For instance, many people have learned to function on insufficient rest or to work in the presence of enormous distractions or wretched environmental conditions (extreme heat, cold, noise, vibration, and so on).
These conditions become normalized and accepted by the individual. But, when the limits of human capabilities are exceeded (fatigue or loss of situational awareness, for example), the likelihood of error increases. The common characteristics of human nature addressed below are especially accentuated when work is performed in a complex work environment.
Stress
Stress in itself is not a bad thing. Some stress is normal and healthy. Stress may result in more focused attention, which in some situations could actually be beneficial to performance. The problem with stress is that it can accumulate and overpower a person, thus becoming detrimental to performance. Stress can be seen as the body’s mental and physical response to a perceived threat(s) in the environment. The important word is perceived, the perception one has about his or her ability to cope with the threat. Stress increases as familiarity with a situation decreases. It can result in panic, inhibiting the ability to effectively sense, perceive, recall, think, or act. Anxiety and fear usually follow when an individual feels unable to respond successfully.
Besides anxiety and fear, memory lapses are among the first symptoms. The inability to think critically or to perform physical acts with accuracy soon follows. Avoidance of Mental Strain. Humans are reluctant to engage in lengthy, concentrated thinking, as it requires high levels of attention for extended periods. Thinking is a slow, laborious process that requires great effort.
Consequently, people tend to look for familiar patterns and apply well-tried solutions to a problem. There is the temptation to settle for satisfactory solutions rather than continue seeking better solutions. The mental biases, or shortcuts, often used to reduce mental effort and expedite decision-making include:
Assumptions – A condition taken for granted or accepted as true without verification of the facts.
Habit – An unconscious pattern of behavior acquired through frequent repetition.
Confirmation bias – The reluctance to abandon a current solution—to change one’s mind—in light of conflicting information due to the investment of time and effort in the current solution. This bias orients the mind to “see” evidence that supports the original supposition and to ignore or rationalize away conflicting data.
Similarity bias – The tendency to recall solutions from situations that appear similar to those that have proved useful from past experience.
Frequency bias – A gamble that a frequently used solution will work; giving greater weight to information that occurs more frequently or is more recent.
Availability bias – The tendency to settle on solutions or courses of action that readily come to mind and appear satisfactory; more weight is placed on information that is available (even though it could be wrong).3 4 This is related to a tendency to assign a cause-effect relationship between two events because they occur almost at the same time.
Limited Working Memory
The mind’s short-term memory is the “workbench” for problem-solving and decision-making. This temporary, attention-demanding storeroom is used to remember new information and is actively involved in learning, storing, and recalling information. Most people can reliably remember a limited number of items at a time, often expressed as 7+1 or -2. The limitations of short-term memory are at the root of forgetfulness; forgetfulness leads to omissions when performing tasks. Applying place-keeping techniques while using complex procedures compensates for this human limitation.
Limited Attention Resources
The limited ability to concentrate on two or more activities challenges the ability to process the information needed to solve problems. Studies have shown that the mind can concentrate on, at most, two or three things simultaneously. Attention is a limited commodity—if it is strongly drawn to one particular thing, it is necessarily withdrawn from other competing concerns. Humans can only attend to a very small proportion of the available sensory data. Also, preoccupation with some demanding sensory input or distraction by some current thoughts or worries can capture attention. Attention focus (concentration) is hard to sustain for extended periods of time. The ability to concentrate depends very much upon the intrinsic interest of the current object of attention. Self-checking (Stop, Think, Act, Review) is an effective tool for helping individuals maintain attention.
Mind-Set
People tend to focus more on what they want to accomplish (a goal) and less on what needs to be avoided because human beings are primarily goal-oriented. As such, people tend to “see” only what the mind expects or wants to see. The human mind seeks order, and once established, it ignores anything outside that mental model. Information that does not fit a mindset may not be noticed; hence, people tend to miss conditions and circumstances that are not expected. Likewise, because they expect certain conditions and circumstances, they tend to see things that are not present. Focusing on goal tends to conceal hazards, leading to an inaccurate perception of risks. Errors, hazards, and consequences usually result from incomplete information or assumptions. If done mindfully, pre-job briefings help people recognize what needs to be avoided and what needs to be accomplished.
Difficulty Seeing One’s Own Error
Individuals, especially when working alone, are particularly susceptible to missing errors. People who are too close to a task or are preoccupied with other things may fail to detect abnormalities. People are encouraged to “focus on the task at hand.” However, this is a two-edged sword. Something may be missed because of our tendency for mindset and limited perspective. Peer-checking and concurrent and independent verification techniques help detect errors that an individual can miss. Engineers and some knowledge workers, by their focus on producing detailed information, can be especially susceptible to not being appropriately self-critical.
Limited Perspective
Humans cannot see all there is to see. The inability of the human mind to perceive all facts pertinent to a decision challenges problem-solving. This is similar to attempting to see all the objects in a locked room through the door’s keyhole. It is technically known as “bounded rationality.”11 Only parts of a problem receive one’s attention while other parts remain hidden to the individual. This limitation causes an inaccurate mental picture, or model, of a problem and leads to underestimating the risk.12 A well-practiced problem-solving methodology is a key element to effective operating team performance during a facility abnormality and also for the management team during meetings to address the problems of operating and maintaining the facility.
Susceptibility To Emotional/Social Factors
Anger and embarrassment adversely influence the team and individual performance. These and other emotional obstacles may weaken problem-solving ability, especially in a group. Pride, embarrassment, and the group may inhibit critical evaluation of proposed solutions, possibly resulting in team errors.
Fatigue
People get tired. In general, Americans are working longer hours now than a generation ago and are sleeping less. Physical, emotional, and mental fatigue can lead to error and poor judgment. Fatigue is affected by both on-the-job demands (production pressures, environment, and reduced staffing) and off-duty lifestyle (diet and sleep habits).13 Fatigue leads to impaired reasoning and decision-making, impaired vigilance and attention, slowed mental functioning and reaction time, loss of situational awareness, and adoption of shortcuts. Acquiring adequate rest is an important factor in reducing the individual error rates.
Presenteeism
Some employees will be present in the need to belong to the workplace despite a diminished capacity to perform their jobs due to illness or injury. The tendency of people to continue working with minor health problems can be exacerbated by lack of sick leave, a backlog of work, or poor access to medical care, and can lead to employees working with significant impairments. Extreme cases can include individuals who fail to seek care for chronic and disabling physical and mental health problems in order to keep working.