Among service providers, healthcare is unique: patients are often placed in vulnerable situations with their doctors and other health professionals. Health is a private, sensitive topic requiring an awareness and understanding of the underlying mechanisms of patient care. Although healthcare professionals often do their best to provide the best care, psychology can often affect the ways in which they treat their patients, and the ways their patients perceive that treatment. For example, roughly 25% of nurses have reported being “repulsed” by an obese patient (Puhl & Brownell, 2001), adding 3 extra minutes to a colonoscopy can actually make it a more pleasant experience (Redelmeier et al., 2003), and doctors who have had personal experiences with uncommon diseases are more likely to prescribe screenings related to those diseases for their patients (Ragland et al., 2018). These are not the only examples of seemingly “irrational” behaviours and perceptions that influence the healthcare space. Cognitive biases play a large role in healthcare and understanding these biases is important for improving the healthcare experience.

This article presents 5 cognitive biases influencing the seemingly irrational behavioural trends in healthcare.

The Peak-End Rule

For many children, going to the dentist seems like a scary, painful and unpleasant experience; scarier and more painful than it probably truly is. However, at the end of the visit, when the dentist praises them for being so brave and gives them a sticker or a sweet, it makes the whole experience more bearable. With such a great ending to an otherwise unpleasant experience, the child may remember these visits as bearable, better-than-expected occasions, and be more willing to return in the future. Adults undergo similarly unpleasant medical procedures, for instance the dreaded colonoscopy. Luckily, just as a sweet treat can make the dentist a less intimidating place, there are strategies that can improve an adult’s perception of the pleasantness of an uncomfortable colonoscopy. One study found that patients who underwent what was otherwise a normal colonoscopy procedure, except with the addition of three slightly less unpleasant minutes added at the end, rated their experience as less unpleasant overall than patients who underwent the standard, shorter procedure (Redelmeier et al., 2003). Why?

The peak-end rule changes the way individuals remember and evaluate a treatment. According to this bias, individuals judge their experience based on how they felt at its (emotional) ‘peak’ and at its end (the final stimulus), rather than by the average comfort of the visit. The better experience the individuals had at the end of the treatment, the less likely it is that they will remember it as unpleasant. Not moving the medical scope for three minutes at the end of the colonoscopy created a sensation that was uncomfortable, but was less painful than the rest of the procedure. Despite this 3 minute extension, patients remember it as a more bearable visit and are more likely to return in the future because the last thing they experienced was more pleasant.

The Licensing Effect

If you’ve ever been on a diet, you’ll be familiar with cheating. After days of maintaining your diet, eating salads and forgoing desserts, your friend asks if you want a piece of birthday cake and you think to yourself “I’ve been good recently, it’s ok if I have just one piece!” This feeling is not just found in dieters. Everyone feels that their past good actions warrant a small forbidden reward from time to time, and patients are no different. A study investigating people with a rare, terminal lung disease found that patients who previously engaged in “good” behaviour, such as improving their diet, were on average 17% more likely to engage in “bad” behaviour, for example not beginning their prescribed treatment (Genentech). But why do we feel entitled to a forbidden treat, or to disregard our doctor’s orders, after we’ve been good?

The licensing effect (also known as self licensing or moral licensing) describes the phenomenon whereby people feel entitled to engage in some “bad” behaviours after they have done something they perceive as “good”. Being good reinforces a person’s positive self-image and “balances” the perceived morality of their actions, allowing them the room to justify an action they know is not good for them, or one that is not in their best interest. The terminal lung disease patients mentioned above maintained their positive self-image by improving their health through keeping a proper diet, then used that enhanced self-image to justify delaying their doctor’s prescribed treatment.

The Horn Effect

“He must be lazy and probably eats too much!” We often hear that obese people can be judged in a very harsh way by society. They can be perceived as unmotivated or depressed, not having enough self-control, and are often blamed for their extra kilos. Several studies have shown that the prejudice about overweight people is common among medical professionals too, which can result in poorer patient care. 24% of the nurses said they are “repulsed” by an obese person, 66% of physicians thought obese people have a lack of self-control (Puhl & Brownell, 2001). Based on another study, the majority of the doctors preferred not to treat overweight patients and did not expect success when they were responsible for their management. This attitude can affect the quality of patient care, for instance not believing overweight individuals when they express pain, or by assuming that their weight is the root cause of all of their medical problems. Why are even experts prejudiced?

The horn effect is about the tendency to have prejudicial assumptions about someone based on a single negative trait, in this case, the assessment of the person as being overweight or obese. As a result of this cognitive bias, society (and even medical professionals!) automatically endows the overweight with more negative personality traits and characteristics. The stigmatization of obesity results in widespread discrimination, including in patient care. Moreover, it demotivates people to go for regular preventive medical check ups. This bias appears in other areas of our lives as well. For example, parents of overweight children tend to provide them less support for college than parents do for their thinner children (Puhl & Brownell, 2001).

Overconfidence Bias

If you drive a car, you might be surprised how many bad drivers are on the road, and you might consider yourself as a better-than-average driver. You are not alone. 93% of people also believe they are better than average drivers (Svenson, 1981). But, if you’re doing the math, then you know that not all of these people can be correct. If we all had an accurate idea about our abilities, only 50% of us could say that we are above average (or, more accurately, the median)! People often have a skewed perception of their own abilities, believing themselves to be better than they really are. But this phenomenon is not only prevalent on the street.

In the realm of healthcare, the majority of people do not follow the medical recommendation and do not go to regular preventive medical check-ups, at least not as often as is recommended by the medical community. It is well-known that prevention is particularly important as diagnosing a disease in time makes the treatment more effective and increases the chances of being cured. Still, many people believe that they are unlikely to develop medical problems, and this is especially true of younger people, and those who are not actively experiencing symptoms (Sandroni & Squintani, 2004). And people who believe going to a preventive screening is unnecessary, are much less likely to go. This overly confident attitude is not uncommon among health workers either; according to a study, about one third of them overestimate their own abilities relative to their peers (Kovacs et al., 2020). Why?

Overconfidence bias is a form of miscalibration of subjective probabilities. It is about the tendency that an individual’s subjective confidence in his or her judgments is consistently larger than the objective accuracy of those judgments. People are less likely to go to the doctor for medical checkups because they are overconfident. In addition, healthcare workers with overconfidence bias are 26% less likely to manage patients correctly and exert less effort in clinical practice (Kovacs et al., 2020).

Availability bias

There are ways in which this overconfidence can diminish. One event that can reduce overconfidence is personal experience with medical problems. After someone from our social circle is diagnosed with a certain disease (especially if that person is of our age), the perceived probability that it can happen to us too increases, even when the objective probability of the disease has not changed. This personal experience makes medical problems more salient and more top-of-mind, leading to heightened awareness and heightened perception that we may be vulnerable as well. Particularly salient life events, such as a friend or family member becoming seriously ill, increases the “availability” of thoughts related to serious illness in our minds, making them more common, and making them seem much more likely. This cognitive bias can affect medical professionals too; as according to a study, it can influence physicians’ cancer screening recommendations. Doctors with personal cancer experience, such as cancer among friends, family, or coworkers are 17% more likely to act against the established guidelines and recommend ovarian cancer screening to low-risk women (Ragland et al., 2018). Why do we overestimate the probability of a disease as a result of personal experience?

Availability bias is about the tendency to judge probabilities and use information on immediate examples that come to mind when evaluating a specific topic, concept, method or decision. When there is more “available” information about personal experience with a particular disease, people tend to overweight judgements (probabilities) of that disease based on more recent, or impactful, information.

These cognitive biases are only a few examples of how our judgements, as patients or as medical providers, are influenced by our psychology. In order to improve the way healthcare is delivered, understanding these many “irrationalities” is important.