Confirmation Bias: Seeing What We Want to Believe

Confirmation BiasBelieve it or not, we can’t always trust what we see or hear. Our memory is influenced by our expectations (Eysenck & Keane, 2015).

Confirmation bias is a widely recognized phenomenon and refers to our tendency to seek out evidence in line with our current beliefs and stick to ideas even when the data contradicts them (Lidén, 2023).

Evolutionary and cognitive psychologists agree that we naturally tend to be selective and look for information we already know (Buss, 2016).

This article explores this tendency, how it happens, why it matters, and what we can do to get better at recognizing it and reducing its impact.

Before you continue, we thought you might like to download our three Positive CBT Exercises for free. These science-based exercises will provide you with detailed insight into positive Cognitive-Behavioral Therapy (CBT) and give you the tools to apply it in your therapy or coaching.

Understanding Confirmation Bias

We can understand the confirmation bias definition as the human tendency “to seek out, to interpret, to favor, and to selectively recall information that confirms beliefs they already hold, while avoiding or ignoring information that disconfirms these beliefs” (Gabriel & O’Connor, 2024, p. 1).


While it has been known and accepted since at least the 17th century that humans are inclined to form and hold on to ideas and beliefs — often tenaciously — even when faced with contradictory evidence, the term “confirmation bias” only became popular in the 1960s with the work of cognitive psychologist Peter Cathcart Wason (Lidén, 2023).

Wason’s (1960) famous 2–4–6 experiment was devised to investigate the nature of hypothesis testing.

Participants were given the numbers 2, 4, and 6 and told the numbers adhered to a rule.

They were then asked to arrive at a hypothesis explaining the sequence and try a new three-number series to test their rule (Wason, 1960; Lidén, 2023).

For example, if a participant thought the second number was twice that of the first and the third number was three times greater, they might suggest the numbers 10, 20, and 30.

However, if another participant thought it was a simple series increasing by two each time, they might suggest 13, 15, and 17 (Wason, 1960; Lidén, 2023).

The actual rule is more straightforward; the numbers are in ascending order. That’s all.

As we typically offer tests that confirm our initial beliefs, both example hypotheses appear to work, even if they are not the answer (Wason, 1960; Lidén, 2023).

The experiment demonstrates our confirmation bias; we seek information confirming our existing beliefs or hypotheses rather than challenging or disproving them (Lidén, 2023).

In the decades since, and with developments in cognitive science, we have come to understand that people don’t typically have everything they need, “and even if they did, they would not be able to use all the information due to constraints in the environment, attention, or memory” (Lidén, 2023, p. 8).

Instead, we rely on heuristics. Such “rules of thumb” are easy to apply and fairly accurate, yet they can potentially result in systematic and serious biases and errors in judgment (Lidén, 2023; Eysenck & Keane, 2015).

Confirmation bias in context

Confirmation bias is one of several cognitive biases’(Lidén, 2023).

They are important because researchers have recognized that “vulnerability to clinical anxiety and depression depends in part on various cognitive biases” and that mental health treatments such as CBT should support the goals of reducing them (Eysenck & Keane, 2015, p. 668).

Cognitive biases include (Eysenck & Keane, 2015):

  • Attentional bias
    Attending to threat-related stimuli more than neutral stimuli
  • Interpretive bias
    Interpreting ambiguous stimuli, situations, and events as threatening
  • Explicit memory bias
    The likelihood of retrieving mostly unpleasant thoughts rather than positive ones
  • Implicit memory bias
    The tendency to perform better for negative or threatening information on memory tests

Individuals possessing all four biases focus too much on environmental threats, interpret most incidents as concerning, and identify themselves as having experienced mostly unpleasant past events (Eysenck & Keane, 2015).

Similarly, confirmation bias means that individuals give too much weight to evidence that confirms their preconceptions or hypotheses, even incorrect and unhelpful ones. It can lead to poor decision-making because it limits their ability to consider alternative viewpoints or evidence that contradicts their beliefs (Lidén, 2023).

Unsurprisingly, such a negative outlook or bias will lead to unhealthy outcomes, including anxiety and depression (Eysenck & Keane, 2015).

Check out Tali Sharot’s video for a deeper dive.

Facts don't win fights - but this can - The Well

Fascinating Confirmation Bias Examples

Confirmation bias is commonplace and typically has a low impact, yet there are times when it is significant and newsworthy (Eysenck & Keane, 2015; Lidén, 2023).

Limits of information

In 2005, terrorists detonated four bombs in London (three on the London Underground and one on a bus), killing 52 and injuring 700 civilians. In the chaotic weeks that followed, a further attempt failed to detonate a suicide bomb, and the individual got away (Lidén, 2023).

Unsurprisingly, a mass hunt was launched to capture the escaped bomber, and many suspects came under surveillance. Yet, the security services made several significant mistakes.

On July 22, 2005, a man living in the same house as two suspects and bearing a resemblance to one of them was shot dead on an Underground train by officers.

“The context with the previous bombings, the available intelligence, and the pre-operation briefings, created expectations that the surveillance team would spot a suicide bomber leaving the doorway” (Lidén, 2023, p. 37).

The wrong man died because the officers involved failed to see the limits of the information available to them at the time.

Witness identification

In 1976, factory worker John Demjanjuk from Cleveland, Ohio, was identified as a Nazi war criminal known as Ivan the Terrible, perpetrator of many killings within prison camps in the Second World War (Lidén, 2023).

Due to the individual’s denial and limited evidence, the case rested on proof of identity via a photo line-up. However, it became known that “Ivan the Terrible” had a round face and was bald.

As the defendant was the only individual who matched the description, he was chosen by all the witnesses (Lidén, 2023).

Whether or not the witnesses were genuinely able to identify the factory worker as the criminal became irrelevant. The case centered around the unfairness of the line-up and the confirmation bias that resulted from the information they had been given (Lidén, 2023).

Years later, in 2012, following continuing challenges to his identity, John Demjanjuk died pending an appeal for his conviction in a German court. His identity remained unclear as the confirmation bias remained (“Ivan the Terrible,” 2024).

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10 Reasons We Fall for It

Confirmation bias can significantly impact our own and others’ lives (Lidén, 2023; Kappes et al., 2020).

For that reason, it is helpful to understand why it happens and the psychological factors involved. Research confirms that people (Lidén, 2023; Kappes et al., 2020; Eysenck & Keane, 2015):

  1. Don’t like to let go of their initial hypothesis
  2. Prefer to use as much information as is initially available, often resulting in a too specific hypothesis
  3. Show confirmation bias more on their hypothesis than others
  4. Are more likely to adopt a confirmation bias when under high cognitive load
  5. With a lower degree of intelligence are more likely to engage in confirmation bias (most likely due to being less able to manage higher cognitive loads and see the overall picture)
  6. With cognitive impairments are more impacted by confirmation bias
  7. Are often unable to actively consider and understand all relevant information to challenge the existing hypothesis or make a new one
  8. Are influenced by their emotions and motivations and potentially “blinded” to the facts
  9. Are biased by existing thoughts and beliefs (sometimes cultural), even if incorrect
  10. Are influenced by the beliefs and arguments of those around them

10 Steps to Recognizing and Reducing Confirmation Bias

Recognize confirmation biasThe following steps and approaches can help identify and reduce the effect of confirmation bias (Lidén, 2023; Rist, 2023).

  1. Recognize that confirmation bias exists and understand its impact on decision-making and how you interpret information. ​
  2. Actively seek out and consider different viewpoints, opinions, and sources of information that challenge your existing beliefs and hypotheses. ​
  3. Develop critical thinking skills that evaluate evidence and arguments objectively without favoring preconceived notions or desired outcomes.
  4. Be aware of your biases and open to questioning your beliefs and assumptions.
  5. Explore alternative explanations or hypotheses that may contradict your initial beliefs or interpretations.
  6. Welcome feedback and criticism from others, even if they challenge your ideas; recognize it as an opportunity to learn and grow.
  7. Apply systematic and rigorous methods to gather and analyze data, ensuring your conclusions are evidence-based rather than a result of personal biases.
  8. Engage in collaborative discussions and debates with individuals with different perspectives to help see other viewpoints and challenge your biases.
  9. Continuously seek new information and update your knowledge base to avoid becoming entrenched and support more-informed decision-making.
  10. Practice analytical thinking, questioning assumptions, evaluating evidence objectively, and considering alternate explanations.

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How Confirmation Bias Impacts Research

As far back as 1968, Karl Popper recognized that falsifiability (being able to prove that something can be incorrect or false) is crucial to all scientific inquiry, impacting researchers’ behavior and experimental outcomes.

As scientists, Popper argued, we should focus on looking for examples of why a theory does not work instead of seeking confirmation of its correctness. More recently, researchers have also considered that when findings suggest a theory is false, it may be due to issues with the experimental design or data accuracy (Eysenck & Keane, 2015).

Yet, confirmation bias has been an issue for a long time in scientific discovery and remains a challenge.

When researchers looked back at the work of Alexander Graham Bell in developing the telephone, they found that, due to confirmation bias, he ignored promising new approaches in favor of his tried-and-tested ones. It ultimately led to Thomas Edison being the first to develop the forerunner of today’s telephone (Eysenck & Keane, 2015).

More recently, a study showed that 88% of professional scientists working on issues in molecular biology responded to unexpected and inconsistent findings by blaming their experimental methods; they ignored the suggestion that they may need to modify, or even replace, their theories (Eysenck & Keane, 2015).

However, when those same scientists changed their approach yet obtained similarly inconsistent results, 61% revisited their theoretical assumptions (Eysenck & Keane, 2015).

Failure to report null research findings is also a problem. It is known as the “file drawer problem” because data remains unseen in the bottom drawer as the researcher does not attempt to get findings published or because journals show no interest in them (Lidén, 2023).

Can Confirmation Bias Be Good?

Positive confirmation biasThere are no doubt evolutionary reasons for our confirmation bias, yet we remain unclear precisely what they are (Peters, 2022).

Researchers have recognized several potential benefits that arise from our natural inclination to seek out confirmation that we are right, including (Peters, 2022; Gabriel & O’Connor, 2024; Bergerot et al., 2023):

  • Assisting in the personal development of individuals by reinforcing their positive self-conceptions and traits
  • Helping individuals shape social structures by persuading others to adopt their viewpoints
  • Supporting increased confidence by reinforcing individuals’ beliefs and ignoring contradictory evidence
  • Contributing to social conformity and stability by reinforcing shared beliefs and values within a group, potentially boosting cooperation and coordination
  • Encouraging decision-making by removing uncertainty and doubt
  • Increasing the knowledge-producing capacity of a group by supporting a deeper exploration of individual members’ perspectives

It’s vital to note that the possible benefits also have their limitations. They potentially favor the individual at the cost of others’ needs while potentially distorting and hindering the formation of well-founded beliefs (Peters, 2022).

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Resources From

We have many resources for coaches and therapists to help individuals and groups understand and manage their biases.

Why not download our free 3 Positive CBT Exercises Pack and try out the powerful tools contained within? Some examples include the following:

  • Re-Framing Critical Self-Talk 
    Self-criticism typically involves judgment and self-blame regarding our shortcomings (real or imagined), such as our inability to accomplish personal goals and meet others’ expectations. In this exercise, we use self-talk to help us reduce self-criticism and cultivate a kinder, compassionate relationship with ourselves.
  • Solution-Focused Guided Imagery
    Solution-focused therapy assumes we have the resources required to resolve our issues. Here, we learn how to connect with our strengths and overcome the challenges we face.

Other free resources include:

  • The What-If Bias
    We often get caught up in our negative biases, thinking about potentially dire outcomes rather than adopting rational beliefs. This exercise helps us regain a more realistic and balanced perspective.
  • Becoming Aware of Assumptions
    We all bring biases into our daily lives, particularly conversations. In this helpful exercise, we picture how things might be in five years to put them into context.

More extensive versions of the following tools are available with a subscription to the Positive Psychology Toolkit©, but they are described briefly below.

  • Increasing Awareness of Cognitive Distortions

Cognitive distortions refer to our biased thinking about ourselves and our environment. This tool helps reduce the effect of the distortions by dismantling them.

    • Step one – Begin by exploring cognitive distortions, such as all-or-nothing thinking, jumping to conclusions, and catastrophizing.
    • Step two – Next, identify the cognitive distortions relevant to your situation.
    • Step three – Reflect on your thinking patterns, how they could harm you, and how you interact with others.
  • Finding Silver Linings

We tend to dwell on the things that go wrong in our lives. We may even begin to think our days are filled with mishaps and disappointments.

Rather than solely focusing on things that have gone wrong, it can help to look on the bright side. Try the following:

    • Step one – Create a list of things that make you feel life is worthwhile, enjoyable, and meaningful.
    • Step two – Think of a time when things didn’t go how you wanted them to.
    • Step three – Reflect on what this difficulty cost you.
    • Step four – Finally, consider what you may have gained from the experience. Write down three positives.

If you’re looking for more science-based ways to help others through CBT, check out this collection of 17 validated positive CBT tools for practitioners. Use them to help others overcome unhelpful thoughts and feelings and develop more positive behaviors.

A Take-Home Message

We can’t always trust what we hear or see because our beliefs and expectations influence so much of how we interact with the world.

Confirmation bias refers to our natural inclination to seek out and focus on what confirms our beliefs, often ignoring anything that contradicts them.

While we have known of its effect for over 200 years, it still receives considerable research focus because of its impact on us individually and as a society, often causing us to make poor decisions and leading to damaging outcomes.

Confirmation bias has several sources and triggers, including our unwillingness to relinquish our initial beliefs (even when incorrect), preference for personal hypotheses, cognitive load, and cognitive impairments.

However, most of us can reduce confirmation bias with practice and training. We can become more aware of such inclinations and seek out challenges or alternate explanations for our beliefs.

It matters because confirmation bias can influence how we work, the research we base decisions on, and how our clients manage their relationships with others and their environments.

We hope you enjoyed reading this article. For more information, don’t forget to download our three Positive CBT Exercises for free.

  • Bergerot, C., Barfuss, W., & Romanczuk, P. (2023). Moderate confirmation bias enhances collective decision-making. biorXiv.
  • Buss, D. M. (2016). Evolutionary psychology: The new science of the mind. Routledge.
  • Eysenck, M. W., & Keane, M. T. (2015). Cognitive psychology: A student’s handbook. Psychology Press.
  • Gabriel, N., & O’Connor, C. (2024). Can confirmation bias improve group learning? PhilSci Archive.
  • Ivan the Terrible (Treblinka guard). (2024). In Wikipedia.
  • Kappes, A., Harvey, A. H., Lohrenz, T., Montague, P. R., & Sharot, T. (2020). Confirmation bias in the utilization of others’ opinion strength. Nature Neuroscience, 23(1), 130–137.
  • Lidén, M. (2023). Confirmation bias in criminal cases. Oxford University Press.
  • Peters, U. (2022). What is the function of confirmation bias? Erkenntnis, 87, 1351–1376.
  • Popper, K. R. (1968). The logic of scientific discovery. Hutchinson.
  • Rist, T. (2023). Confirmation bias studies: Towards a scientific theory in the humanities. SN Social Sciences, 3(8).
  • Wason, P. C. (1960). On the failure to eliminate hypotheses in a conceptual task. Quarterly Journal of Experimental Psychology, 12(3), 129–140.

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