Cognitive Bias: How We Are Wired to Misjudge

Confirmation bias is the tendency to interpret new information as confirmation of your preexisting beliefs and opinions while giving disproportionately less consideration to alternative possibilities.

Real-World Examples

Since Watson’s 1960 experiment, real-world examples of confirmation bias have gained attention.

This bias often seeps into the research world when psychologists selectively interpret data or ignore unfavorable data to produce results that support their initial hypothesis.

Confirmation bias is also incredibly pervasive on the internet, particularly with social media. We tend to read online news articles that support our beliefs and fail to seek out sources that challenge them.

Various social media platforms, such as Facebook, help reinforce our confirmation bias by feeding us stories that we are likely to agree with – further pushing us down these echo chambers of political polarization.

Some examples of confirmation bias are especially harmful, specifically in the context of the law. For example, a detective may identify a suspect early in an investigation, seek out confirming evidence, and downplay falsifying evidence.

Experiments

The confirmation bias dates back to 1960 when Peter Wason challenged participants to identify a rule applying to triples of numbers.

People were first told that the sequences 2, 4, 6 fit the rule, and they then had to generate triples of their own and were told whether that sequence fits the rule. The rule was simple: any ascending sequence.

But not only did participants have an unusually difficult time realizing this and instead devised overly-complicated hypotheses, they also only generated triples that confirmed their preexisting hypothesis (Wason, 1960).

Explanations

But why does confirmation bias occur? It’s partially due to the effect of desire on our beliefs. In other words, certain desired conclusions (ones that support our beliefs) are more likely to be processed by the brain and labeled as true (Nickerson, 1998).

This motivational explanation is often coupled with a more cognitive theory.

The cognitive explanation argues that because our minds can only focus on one thing at a time, it is hard to parallel process (see information processing for more information) alternate hypotheses, so, as a result, we only process the information that aligns with our beliefs (Nickerson, 1998).

Another theory explains confirmation bias as a way of enhancing and protecting our self-esteem.

As with the self-serving bias (see more below), our minds choose to reinforce our preexisting ideas because being right helps preserve our sense of self-esteem, which is important for feeling secure in the world and maintaining positive relationships (Casad, 2019).

Although confirmation bias has obvious consequences, you can still work towards overcoming it by being open-minded and willing to look at situations from a different perspective than you might be used to (Luippold et al., 2015).

Even though this bias is unconscious, training your mind to become more flexible in its thought patterns will help mitigate the effects of this bias.

Hindsight bias refers to the tendency to perceive past events as more predictable than they actually were (Roese & Vohs, 2012). There are cognitive and motivational explanations for why we ascribe so much certainty to knowing the outcome of an event only once the event is completed.

Real-World Examples

When sports fans know the outcome of a game, they often question certain decisions coaches make that they otherwise would not have questioned or second-guessed.

And fans are also quick to remark that they knew their team was going to win or lose, but, of course, they only make this statement after their team actually did win or lose.

Although research studies have demonstrated that the hindsight bias isn’t necessarily mitigated by pure recognition of the bias (Pohl & Hell, 1996).

You can still make a conscious effort to remind yourself that you can’t predict the future and motivate yourself to consider alternate explanations.

It’s important to do all we can to reduce this bias because when we are overly confident about our ability to predict outcomes, we might make future risky decisions that could have potentially dangerous outcomes.

Experiments

Building on Tversky and Kahneman’s growing list of heuristics, researchers Baruch Fischhoff and Ruth Beyth-Marom (1975) were the first to directly investigate the hindsight bias in the empirical setting.

The team asked participants to judge the likelihood of several different outcomes of former U.S. president Richard Nixon’s visit to Beijing and Moscow.

After Nixon returned back to the States, participants were asked to recall the likelihood of each outcome they had initially assigned.

Fischhoff and Beyth found that for events that actually occurred, participants greatly overestimated the initial likelihood they assigned to those events.

That same year, Fischhoff (1975) introduced a new method for testing the hindsight bias – one that researchers still use today.

Participants are given a short story with four possible outcomes, and they are told that one is true. When they are then asked to assign the likelihood of each specific outcome, they regularly assign a higher likelihood to whichever outcome they have been told is true, regardless of how likely it actually is.

But hindsight bias does not only exist in artificial settings. In 1993, Dorothee Dietrich and Matthew Olsen asked college students to predict how the U.S. Senate would vote on the confirmation of Supreme Court nominee Clarence Thomas.

Before the vote, 58% of participants predicted that he would be confirmed, but after his actual confirmation, 78% of students said that they thought he would be approved – a prime example of the hindsight bias. And this form of bias extends beyond the research world.

Explanations

From the cognitive perspective, hindsight bias may result from distortions of memories of what we knew or believed to know before an event occurred (Inman, 2016).

It is easier to recall information that is consistent with our current knowledge, so our memories become warped in a way that agrees with what actually did happen.

Motivational explanations of the hindsight bias point to the fact that we are motivated to live in a predictable world (Inman, 2016).

When surprising outcomes arise, our expectations are violated, and we may experience negative reactions as a result. Thus, we rely on the hindsight bias to avoid these adverse responses to certain unanticipated events and reassure ourselves that we actually did know what was going to happen.

Self-serving bias is the tendency to take personal responsibility for positive outcomes and blame external factors for negative outcomes.

You would be right to ask how this is similar to the fundamental attribution error (Ross, 1977), which identifies our tendency to overemphasize internal factors for other people’s behavior while attributing external factors to our own.

The distinction is that the self-serving bias is concerned with valence. That is, how good or bad an event or situation is. And it is also only concerned with events for which you are the actor.

In other words, if a driver cuts in front of you as the light turns green, the fundamental attribution error might cause you to think that they are a bad person and not consider the possibility that they were late for work.

On the other hand, the self-serving bias is exercised when you are the actor. In this example, you would be the driver cutting in front of the other car, which you would tell yourself is because you are late (an external attribution to a negative event) as opposed to it being because you are a bad person.

Real-World Examples

From sports to the workplace, self-serving bias is incredibly common. For example, athletes are quick to take responsibility for personal wins, attributing their successes to their hard work and mental toughness, but point to external factors, such as unfair calls or bad weather, when they lose (Allen et al., 2020).

In the workplace, people attribute internal factors when they have hired for a job but external factors when they are fired (Furnham, 1982). And in the office itself, workplace conflicts are given external attributions, and successes, whether a persuasive presentation or a promotion, are awarded internal explanations (Walther & Bazarova, 2007).

Additionally, self-serving bias is more prevalent in individualistic cultures, which place emphasis on self-esteem levels and individual goals, and it is less prevalent among individuals with depression (Mezulis et al., 2004), who are more likely to take responsibility for negative outcomes.

Overcoming this bias can be difficult because it is at the expense of our self-esteem. Nevertheless, practicing self-compassion – treating yourself with kindness even when you fall short or fail – can help reduce the self-serving bias (Neff, 2003).

Explanations

The leading explanation for the self-serving bias is that it is a way of protecting our self-esteem (similar to one of the explanations for the confirmation bias).

We are quick to take credit for positive outcomes and divert the blame for negative ones to boost and preserve our individual ego, which is necessary for confidence and healthy relationships with others (Heider, 1982).

Another theory argues that self-serving bias occurs when surprising events arise. When certain outcomes run counter to our expectations, we ascribe external factors, but when outcomes are in line with our expectations, we attribute internal factors (Miller & Ross, 1975).

An extension of this theory asserts that we are naturally optimistic, so negative outcomes come as a surprise and receive external attributions as a result.

individualistic cultures is closely related to the decision-making process. It occurs when we rely too heavily on either pre-existing information or the first piece of information (the anchor) when making a decision.

For example, if you first see a T-shirt that costs $1,000 and then see a second one that costs $100, you’re more likely to see the second shirt as cheap as you would if the first shirt you saw was $120. Here, the price of the first shirt influences how you view the second.

Real-World Examples

Sarah is looking to buy a used car. The first dealership she visits has a used sedan listed for $19,000. Sarah takes this initial listing price as an anchor and uses it to evaluate prices at other dealerships.

When she sees another similar used sedan priced at $18,000, that price seems like a good bargain compared to the $19,000 anchor price she saw first, even though the actual market value is closer to $16,000.

When Sarah finds a comparable used sedan priced at $15,500, she continues perceiving that price as cheap compared to her anchored reference price.

Ultimately, Sarah purchases the $18,000 sedan, overlooking that all of the prices seemed like bargains only in relation to the initial high anchor price.

The key elements that demonstrate anchoring bias here are:

1. Sarah establishes an initial reference price based on the first listing she sees ($19k)
2. She uses that initial price as her comparison/anchor for evaluating subsequent prices
3. This biases her perception of the market value of the cars she looks at after the initial anchor is set
4. She makes a purchase decision aligned with her anchored expectations rather than a more objective market value

Explanations

Multiple theories seek to explain the existence of this bias.

One theory, known as anchoring and adjustment, argues that once an anchor is established, people insufficiently adjust away from it to arrive at their final answer, and so their final guess or decision is closer to the anchor than it otherwise would have been (Tversky & Kahneman, 1992).

And when people experience a greater cognitive load (the amount of information the working memory can hold at any given time; for example, a difficult decision as opposed to an easy one), they are more susceptible to the effects of anchoring.

Another theory, selective accessibility, holds that although we assume that the anchor is not a suitable answer (or a suitable price going back to the initial example) when we evaluate the second stimulus (or second shirt), we look for ways in which it is similar or different to the anchor (the price being way different), resulting in the anchoring effect (Mussweiler & Strack, 1999).

A final theory posits that providing an anchor changes someone’s attitudes to be more favorable to the anchor, which then biases future answers to have similar characteristics as the initial anchor.

Although there are many different theories for why we experience anchoring bias, they all agree that it affects our decisions in real ways (Wegner et al., 2001).

Experiments

The first study that brought this bias to light was during one of Tversky and Kahneman’s (1974) initial experiments. They asked participants to compute the product of numbers 1-8 in five seconds, either as 1x2x3… or 8x7x6…

Participants did not have enough time to calculate the answer, so they had to estimate based on their first few calculations.

They found that those who computed the small multiplications first (i.e., 1x2x3…) gave a median estimate of 512, but those who computed the larger multiplications first gave a median estimate of 2,250 (although the actual answer is 40,320).

This demonstrates how the initial few calculations influenced the participant’s final answer.

Availability bias (also commonly referred to as the availability heuristic) refers to the tendency to think that examples of things that readily come to mind are more common than what is actually the case.

In other words, information that comes to mind faster influences the decisions we make about the future. And just like with the hindsight bias, this bias is related to an error of memory.

But instead of being a memory fabrication, it is an overemphasis on a certain memory.

In the workplace, if someone is being considered for a promotion but their boss recalls one bad thing that happened years ago but left a lasting impression, that one event might have an outsized influence on the final decision.

Another common example is buying lottery tickets because the lifestyle and benefits of winning are more readily available in mind (and the potential emotions associated with winning or seeing other people win) than the complex probability calculation of actually winning the lottery (Cherry, 2019).

A final common example that is used to demonstrate the availability heuristic describes how seeing several television shows or news reports about shark attacks (or anything that is sensationalized by the news, such as serial killers or plane crashes) might make you think that this incident is relatively common even though it is not at all.

Regardless, this thinking might make you less inclined to go in the water the next time you go to the beach (Cherry, 2019).

Explanations

As with most cognitive biases, the best way to overcome them is by recognizing the bias and being more cognizant of your thoughts and decisions.

And because we fall victim to this bias when our brain relies on quick mental shortcuts in order to save time, slowing down our thinking and decision-making process is a crucial step to mitigating the effects of the availability heuristic.

Researchers think this bias occurs because the brain is constantly trying to minimize the effort necessary to make decisions, and so we rely on certain memories – ones that we can recall more easily – instead of having to endure the complicated task of calculating statistical probabilities.

Two main types of memories are easier to recall: 1) those that more closely align with the way we see the world and 2) those that evoke more emotion and leave a more lasting impression.

Experiments

This first type of memory was identified in 1973, when Tversky and Kahneman, our cognitive bias pioneers, conducted a study in which they asked participants if more words begin with the letter K or if more words have K as their third letter.

Although many more words have K as their third letter, 70% of participants said that more words begin with K because the ability to recall this is not only easier, but it more closely aligns with the way they see the world (knowing the first letter of any word is infinitely more common than the third letter of any word).

In terms of the second type of memory, the same duo ran an experiment in 1983, 10 years later, where half the participants were asked to guess the likelihood of a massive flood would occur somewhere in North America, and the other half had to guess the likelihood of a flood occurring due to an earthquake in California.

Although the latter is much less likely, participants still said that this would be much more common because they could recall specific, emotionally charged events of earthquakes hitting California, largely due to the news coverage they receive.

Together, these studies highlight how memories that are easier to recall greatly influence our judgments and perceptions about future events.

A final popular form of cognitive bias is inattentional blindness. This occurs when a person fails to notice a stimulus that is in plain sight because their attention is directed elsewhere.

For example, while driving a car, you might be so focused on the road ahead of you that you completely fail to notice a car swerve into your lane of traffic.

Because your attention is directed elsewhere, you aren’t able to react in time, potentially leading to a car accident. Experiencing inattentional blindness has its obvious consequences (as illustrated by this example), but, like all biases, it is not impossible to overcome.

Explanations

Many theories seek to explain why we experience this form of cognitive bias. In reality, it is probably some combination of these explanations.

Conspicuity holds that certain sensory stimuli (such as bright colors) and cognitive stimuli (such as something familiar) are more likely to be processed, and so stimuli that don’t fit into one of these two categories might be missed.

The mental workload theory describes how when we focus a lot of our brain’s mental energy on one stimulus, we are using up our cognitive resources and won’t be able to process another stimulus simultaneously.

Similarly, some psychologists explain how we attend to different stimuli with varying levels of attentional capacity, which might affect our ability to process multiple stimuli simultaneously.

In other words, an experienced driver might be able to see that car swerve into the lane because they are using fewer mental resources to drive, whereas a beginner driver might be using more resources to focus on the road ahead and unable to process that car swerving in.

A final explanation argues that because our attentional and processing resources are limited, our brain dedicates them to what fits into our schemas or our cognitive representations of the world (Cherry, 2020).

Thus, when an unexpected stimulus comes into our line of sight, we might not be able to process it on the conscious level. The following example illustrates how this might happen.

Experiments

The most famous study to demonstrate the inattentional blindness phenomenon is the invisible gorilla study (Most et al., 2001). This experiment asked participants to watch a video of two groups passing a basketball and count how many times the white team passed the ball.

Participants are able to accurately report the number of passes, but what they fail to notice is a gorilla walking directly through the middle of the circle.

Because this would not be expected, and because our brain is using up its resources to count the number of passes, we completely fail to process something right before our eyes.

A real-world example of inattentional blindness occurred in 1995 when Boston police officer Kenny Conley was chasing a suspect and ran by a group of officers who were mistakenly holding down an undercover cop.

Conley was convicted of perjury and obstruction of justice because he supposedly saw the fight between the undercover cop and the other officers and lied about it to protect the officers, but he stood by his word that he really hadn’t seen it (due to inattentional blindness) and was ultimately exonerated (Pickel, 2015).

The key to overcoming inattentional blindness is to maximize your attention by avoiding distractions such as checking your phone. And it is also important to pay attention to what other people might not notice (if you are that driver, don’t always assume that others can see you).

By working on expanding your attention and minimizing unnecessary distractions that will use up your mental resources, you can work towards overcoming this bias.

Preventing Cognitive Bias

• Project Implicit (IAT Test) From Harvard University
• Implicit Association Test From the Social Psychology Network
• Test Yourself for Hidden Bias From Teaching Tolerance

• How The Concept Of Implicit Bias Came Into Being With Dr. Mahzarin Banaji, Harvard University. Author of Blindspot: hidden biases of good people5:28 minutes; includes transcript
• Understanding Your Racial Biases With John Dovidio, PhD, Yale University
  From the American Psychological Association11:09 minutes; includes transcript
• Talking Implicit Bias in Policing With Jack Glaser, Goldman School of Public Policy, University of California Berkeley21:59 minutes
• Implicit Bias: A Factor in Health Communication With Dr. Winston Wong, Kaiser Permanente19:58 minutes
• Bias, Black Lives and Academic Medicine Dr. David Ansell on Your Health Radio (August 1, 2015)21:42 minutes

• Uncovering Hidden Biases Google talk with Dr. Mahzarin Banaji, Harvard University
• Impact of Implicit Bias on the Justice System 9:14 minutes
• Students Speak Up: What Bias Means to Them 2:17 minutes
• Weight Bias in Health Care From Yale University16:56 minutes
• Gender and Racial Bias In Facial Recognition Technology 4:43 minutes

• An implicit bias primer Mitchell, G. (2018). An implicit bias primer. Virginia Journal
  of Social Policy & the Law, 25, 27–59.
• Implicit Association Test at age 7: A methodological and conceptual review Nosek, B. A., Greenwald, A. G., & Banaji, M. R. (2007). The Implicit Association Test at age 7: A methodological and conceptual review. Automatic processes in social thinking and behavior, 4, 265-292.
• Implicit Racial/Ethnic Bias Among Health Care Professionals and Its Influence on Health Care Outcomes: A Systematic Review Hall, W. J., Chapman, M. V., Lee, K. M., Merino, Y. M., Thomas, T. W., Payne, B. K., … & Coyne-Beasley, T. (2015). Implicit racial/ethnic bias among health care professionals and its influence on health care outcomes: a systematic review. American journal of public health, 105 (12), e60-e76.
• Reducing Racial Bias Among Health Care Providers: Lessons
  from Social-Cognitive Psychology Burgess, D., Van Ryn, M., Dovidio, J., & Saha, S. (2007). Reducing racial bias among health care providers: lessons from social-cognitive psychology. Journal of general internal medicine, 22 (6), 882-887.
• Integrating implicit bias into counselor education Boysen, G. A. (2010). Integrating Implicit Bias Into Counselor Education. Counselor Education & Supervision, 49 (4), 210–227.
• Cognitive Biases and Errors as Cause—and Journalistic Best Practices as Effect Christian, S. (2013). Cognitive Biases and Errors as Cause—and Journalistic Best Practices as Effect. Journal of Mass Media Ethics, 28 (3), 160–174.
• Empathy intervention to reduce implicit bias in pre-service teachers Whitford, D. K., & Emerson, A. M. (2019). Empathy Intervention to Reduce Implicit Bias in Pre-Service Teachers. Psychological Reports, 122 (2), 670–688.