What is cognitive bias?

Cognitive biases are tendencies commonly used to acquire and process information by filtering it through one’s own beliefs and experiences. They are flaws in judgment, which studies have shown are caused by memory, social attribution, and statistical errors. Humans develop cognitive biases for many reasons; however, they are frequently the result of a system of heuristic processes (problem-solving strategies) that help the brain to process information quickly. Although heuristics are indeed helpful in problem solving, under conditions of complexity and uncertainty, they are known to produce systematic errors in judgment. Numerous cognitive biases have been identified and shown to be relevant in many health care settings. Specific strategies for heuristic reasoning and associated errors in thinking that are reviewed here have been truncated to those that seem most relevant, in our opinions, to the medical sciences, including orthodontics.

It is important to distinguish cognitive biases from other forms of bias, such as cultural bias, organizational bias, or bias that results from one’s own self-interest. In other words, a cognitive bias does not result from any emotional or intellectual predisposition toward a certain judgment but, rather, from mental procedures for processing information. When psychological experiments show a bias, this does not mean that every judgment by every person will be biased. It means that, in any group of people, there will be bias to a greater or lesser degree in most judgments made by most of the group. On the basis of this kind of experimental evidence, one can only generalize about the tendencies of groups of people and not make statements about how any specific person will make judgments and render decisions. Psychological studies in this field used test subjects from many disciplines, including physicians, stock market analysts, horse-race handicappers, chess masters, research directors, and professional psychologists. This research extends the pioneering work of Kahneman et al. In most cases, the mental tasks performed in these experiments were realistic and domain specific; that is, they are comparable with judgments that specialists in these fields are normally required to make. Although specialists in orthodontics have not been studied, we are thus persuaded that the findings from medicine and nursing most likely apply to the cognitive processes used by orthodontists.

Dual process theories of cognition

Recent studies in cognitive psychology suggest that our brains use 2 distinct and neurologically differentiated systems of understanding. System 1, the heuristic, is automatic, intuitive, parallel, and fast; system 2, the analytic, is rule-based, serial, and slow—ie, consciously deliberate. The theory that seems to be emerging in understanding the functional relationships posits that system 1, through a collection of an indeterminate number of subsystem manipulations, delivers judgments to the conscious mind, where the conscious reasoning processes of system 2 take over to produce its own judgments. System 2 provides the capacity to abstract and decontextualize information. It applies rules and protocols in accordance with explicitly codified instructions, making use of central working memory. Importantly, this system copes efficiently with only 1 task at a time (bounded rationality).

Studies in the medical domain have raised questions as to whether the intuitive and tacit processing of system 1 and the analytical and scientific processing of system 2 are equal partners in producing correct judgments. Research in the nursing literature suggests that nurses rely on both systems equally in real-world decision making. However, cognitive psychologists have generally thought that system 2 takes epistemological precedence over system 1, overriding or inhibiting its responses by default and serving in a supervisory capacity by monitoring and correcting the intuitive judgments. Other studies have demonstrated that the intuitive processes in system 1 will be predominant when dealing with complex and ill-structured tasks that often confront clinicians’ decision making, when information is often lacking and probabilities are unknown. Studies are ongoing to better understand and explain the functional relationships of forming judgments and decision making and to validate whether the dual-process theory truly accounts for the complexities of human thinking operations. But, for now, we concluded that the dual-process theory holds promise in helping to explain judgment biases and errors that predictably occur in human reasoning and provides a helpful model for the study of decision making under uncertainty in orthodontics.

Dual process theories of cognition

Recent studies in cognitive psychology suggest that our brains use 2 distinct and neurologically differentiated systems of understanding. System 1, the heuristic, is automatic, intuitive, parallel, and fast; system 2, the analytic, is rule-based, serial, and slow—ie, consciously deliberate. The theory that seems to be emerging in understanding the functional relationships posits that system 1, through a collection of an indeterminate number of subsystem manipulations, delivers judgments to the conscious mind, where the conscious reasoning processes of system 2 take over to produce its own judgments. System 2 provides the capacity to abstract and decontextualize information. It applies rules and protocols in accordance with explicitly codified instructions, making use of central working memory. Importantly, this system copes efficiently with only 1 task at a time (bounded rationality).

Studies in the medical domain have raised questions as to whether the intuitive and tacit processing of system 1 and the analytical and scientific processing of system 2 are equal partners in producing correct judgments. Research in the nursing literature suggests that nurses rely on both systems equally in real-world decision making. However, cognitive psychologists have generally thought that system 2 takes epistemological precedence over system 1, overriding or inhibiting its responses by default and serving in a supervisory capacity by monitoring and correcting the intuitive judgments. Other studies have demonstrated that the intuitive processes in system 1 will be predominant when dealing with complex and ill-structured tasks that often confront clinicians’ decision making, when information is often lacking and probabilities are unknown. Studies are ongoing to better understand and explain the functional relationships of forming judgments and decision making and to validate whether the dual-process theory truly accounts for the complexities of human thinking operations. But, for now, we concluded that the dual-process theory holds promise in helping to explain judgment biases and errors that predictably occur in human reasoning and provides a helpful model for the study of decision making under uncertainty in orthodontics.

The heuristics and biases tradition

As mentioned previously, the identification of the relationship between cognitive heuristics and bias under uncertainty began with the research program by Kahneman et al. (In 2002, Daniel Kahneman won the Nobel Prize in economics for his work in prospect theory, a theory that explains how people evaluate potential losses and gains under risk). Over the past 4 decades, intense research has been ongoing to explain not only the psychological mechanisms for reasoning, formulation of judgments, and decision making, but also in more recent years to study the neural functions of the brain during these processes. The literature consistently shows that people use a subsystem of intuitive mental routines to cope with the complexity inherent in most decisions. These simplifying heuristic mechanisms, although prone to bias and errors, are nonetheless essential in directing our judgment and in most situations will serve us well. The problem that people face is that errors in judgment easily go unchecked (system 2). Again, intuitive reasoning (system 1) relies on experiential, tacit knowledge undergirded by heuristic rules to streamline judgments. However, since not all information is considered in this mental process, heuristics can lead to predictable errors in judgment.

Numerous heuristics and their potential for biasing judgments in health care settings have been extensively cataloged. We have selected several biases and judgment traps that seem relevant to the clinical judgments and decision making in orthodontics to illustrate how each bias theoretically could play out in clinical orthodontics. Each bias (observed behavior) and underlying heuristic (mental construct) is illustrated with real-life scenarios or clinical applications.

Representativeness

People assess the likelihood of an event by the similarity of the occurrence of the event to their stereotypes of similar occurrences. This might, in some cases, be useful as a good first-cut approximation, but it becomes problematic when this heuristic is taken as accurate, complete, and sufficient when there is better information with which to make a more accurate judgment.

A clinical application is the extraction vs nonextraction issue. Because of a certain facial pattern and how it fits or does not fit a provider’s idea of how a face should look, a decision is made not to extract even when there is better information (eg, degree of crowding, position and inclination of incisors, periodontal architecture, and so on). In such a case, the provider decides that “this is a nonextraction face,” and everything else, including subsequent and arguably more significant diagnostic evidence, becomes secondary.

The commission bias

Providers tend to favor action rather than inaction. Commission bias is more likely to occur in someone who is overconfident; it reflects the urge to “do something.” Pressures from colleagues or the patient can augment commission bias and lead to a commitment to action even when related evidence or practice guidelines show that inaction is the best course.

A clinical application is the 1-phase vs 2-phase treatment of Class II patients. The movement toward early treatment of Class II patients by “growing mandibles” via growth modification began in the 1970s. Phase I treatment continued to grow in popularity over the next several decades. When the results of various clinical trials funded by the National Institutes of Health on early treatment cast doubt on the relative efficacy and effectiveness of such treatment, many orthodontists refused to accept the validity of that research. We ignored the evidence, even though it represented the finest studies available to clinical orthodontists. We assumed that the authors of the trials did not know how to properly manage the functional appliances used in the studies, or that the significant variations of subject responses obfuscated the outcomes, or that mean data do not speak to the treatment of individual patients. There are many reasons to explain such illogical behavior, but a large part of the explanation arises from the biases we as providers bring to the table. For some of us, our desire to do something outweighed the evidence that suggested that a Class II malocclusion can be corrected later and in less time. Certainly, immediate treatment can benefit patients psychologically and, perhaps, better protect them from early trauma. However, in the absence of such concerns, it is now accepted that the cost-benefit ratio does not justify routine 2-phase treatment for most patients with Class II malocclusions.

Considering the complexity and controversy surrounding early treatment in particular, it is possible that no 1 heuristic or bias adequately explains our reluctance to accept this reality. A commission bias prompts us to do something, even if it is not necessarily the correct decision. A visceral bias introduces our emotions into the equation and allows positive (or negative) feelings toward our patients to replace or, at least, influence the desired objectivity necessary for good decision making. To both of these common judgment traps, add the possible and subtle influence of a value bias, which is the tendency for people to favor what they hope will happen rather than what they believe will happen. Then one can better understand our collective tendency to practice and promote early correction of Class II malocclusions in spite of mounting and compelling evidence to the contrary.

The overconfidence bias

Overconfidence has been identified as a common judgmental pattern and demonstrated in a wide variety of settings. People often tend to be overly confident about the infallibility of their judgments and the accuracy of their estimations. The consequences can range from annoyance to severe repercussions. Although confidence in our abilities and judgments is necessary for achievement in life, overconfidence about the accuracy of predictions results in setting too narrow a range of possibilities and overlooking probable outcomes. However, tests and disciplines can be built into our thought processes to uncover errors in thinking before they become errors in judgment.

As a clinical application, good examples of this judgment trap can be found at the podiums of many of our national meetings. A clinician with a good original idea is sharing his experience of his new appliance or treatment on a large screen in front of many practitioners. Although not random, his before-and-after case reports are favorable and indeed demonstrate a biologic plausibility for the success of his new treatment. But the second and equally important criterion that must be met for a theory to become reality is for the new idea to withstand the rigors of the scientific method. Without such testing, even the best idea remains opinion and conjecture, even when held and delivered by the most charismatic and earnest person. The fact that almost everything in orthodontics works at least some of the time does not even occur to the speaker. Instead, an air of infallibility and overconfidence sets in, and the need for testing is replaced by the need to get the word out about the extraordinary appliance or therapy, and a promise that “the data are on the way” is quickly composed. A corporate sponsorship increases credibility, and the goal shifts from seeking truth about a potentially better treatment to satisfying the shareholders of the sponsoring corporation.