Confirmation Bias & Motivated Reasoning

Confirmation bias is a cognitive bias where people have a tendency to search out, interpret, or even recall information in a way that reinforces preexisting beliefs. Once a view is formed, people tend to embrace information that confirms that view while ignoring, or even rejecting, information that casts doubt on it. Thus, we don't perceive circumstances objectively. They are always perceived through this filter that favors our currently held beliefs. It is important to note that this effect is stronger for deeply held beliefs and circumstances that elicit a strong emotional response [1].

Motivated reasoning is a cognitive bias which describes our tendency to accept what we want to believe more readily and with less scrutiny than that which we don't want to believe. This is “a form of implicit emotion regulation in which the brain converges on judgments that minimize negative and maximize positive affect states associated with threat to or attainment of motives”[2].

In short, confirmation bias is an implicit tendency to notice information that coincides with our preexisting beliefs and ignore information that doesn't while motivated reasoning is our tendency to readily accept new information that agrees with our worldview and critically analyze that which doesn't. The underlying impetus behind why these biases exist is to minimize cognitive dissonance, which is a result of our innate desire to minimize pain or discomfort (i.e., the pleasure principle [3]). In general, you will find an interplay between all three when people are presented with new information.


1) Let's re-analyze the second example from the post on the availability heuristic as there are more biases worth mentioning in this story:

Terry is a big supporter of the current President, but is unsure about his claims surrounding global warming. In fact, Terry doesn't know much about global warming other than the scientific community doesn't agree with the President's stance on the issue. Furthermore, there's a special election being held in his state this week where he'll have to decided between a “denialist” (i.e., a common trope for someone who doesn't believe in global warming) or an “alarmist” (i.e., a common trope for someone who believes in global warming). At this point in time, Terry is undecided as he has always considered himself an independent voter.

It just so happens that the President has decided to have a rally in a neighboring town a day before the election. As Terry is a fan of the current President's work, he decides to attend. At the rally, the President goes on and on about how global warming is not caused by man and that it has been changing naturally throughout the Earth's history.

After the rally, charged by the President's claims that global warming is a hoax, he decides to do his own “research” on YouTube and comes across a plethora of videos which further confirm the President's statements. What is more, after all of the information that he has received lately about global warming, Terry has decided that this is a large voting issue for him. Thus, following the rally and his YouTube video “research,” Terry goes to the polls the next day and decides to vote for the candidate who denies global warming.

Explanation: Besides the availability heuristic, Terry is also falling victim to confirmation bias and motivated reasoning as well. Terry went to YouTube to specifically look for videos to reinforce his new belief that global warming is a hoax or, at the very least, that it's really nothing to be concerned with. Further, it is highly probable that during his YouTube search Terry came across a number of videos explaining the science of global warming [4]. In this instance, he most likely ignored these videos and if he did end up watching one, dismissed the information without looking too much into it.

Confirmation bias has caused Terry to seek out videos that support his belief that global warming is a hoax and either ignore or readily dismiss the videos that provide the science on the issue. Meanwhile, motivated reasoning influenced Terry into assimilating the denier arguments with ease, while vehemently resisting the pro-science ones.

2) Cheryl was raised in a very religious family who promoted the idea of “Young Earth Creationism” (YEC). Those who subscribe to YEC believe in the literal interpretation of the creation narrative from the Bible's Book of Genesis and believe that God created the Earth in six days. Unfortunately for Cheryl, her position is completely counter to all scientific evidence available demonstrating the Earth to be approximately 4.5 billion years old [5].

Throughout her schooling, Cheryl was required to take a number of science courses where she was exposed to the true age of the Earth. While Cheryl was required to learn the science, she never believed it to be true as it went against everything that her family and religion believed. Moreover, whenever Cheryl felt as though her faith was wavering, she would either attend Church or talk to her parents about the “evidence” supporting the creation story and why modern science has it wrong.

Explanation: Both motivated reasoning and confirmation bias are at play here. Throughout all of her schooling, Cheryl was repeatedly informed about the age of the Earth and how it was reached by way of the scientific method. However, due to her strong conviction that YEC was the true story of how the Earth was created, she dismissed or ignored the scientific information.

In theory, the presentation of information by her teachers that contradicted her deeply held beliefs in YEC led to cognitive dissonance. This dissonance caused internal strife, which needed to be extinguished. Thus, under the influence of motivated reasoning, Cheryl decided to dismiss all of the scientific evidence presented. Furthermore, due to confirmation bias, she then sought out either her parents or Church group in order to reinforce that her belief in YEC is correct.

3) Don, a college student, subscribes to the “Tabula Rasa” or “Blank Slate” hypothesis, which is an epistemological idea that individuals are born without anything built into the mind and that all knowledge comes from experience [6]. In recent years, this has arisen in the debate regarding whether gender* is a social construct or if there are biological reasons for how gender arises. As an individual who believes in the blank slate hypothesis, he believes that gender is completely a social construct and that men and women have no innate differences at birth when it comes to the psychology of the mind.

Recently, he found himself wanting to read more into the gender debate and came across a podcast where two individuals were discussing such things. Don quickly realized that the podcast was leaning heavy towards the biological determinism notion of gender which he found to be quite offensive. The podcast was three hours in length, but he found himself only able to listen to about 30 minutes of it before he called it quits even though they were discussing the science that supports this position.

Following the first podcast, he decided to continue to try and find more information on the gender debate. However, this time around, he searched YouTube specifically to find videos on the Blank Slate hypothesis applied to gender. Needless to say, he was able to get through a number of videos completely over a time period of many hours.

The following day, Don engaged in a debate with a few friends and presented the following argument:

  • I watched these YouTube videos the other day that presents the science on why gender identity is a social construct. Links to a number of studies are even included as well supporting the blank slate approach to gender identity.

  • Therefore, gender is completely a social construct.

*Gender is how an individual identifies (e.g., man, woman, non-binary, etc.). Sex is a biological definition that is dependent upon your reproductive organs (i.e., male, female, intersex).

Explanation: Again, both biases are at play here. While the podcast was presenting the science that supports the idea that biology has a role to play in gender, Don's cognitive dissonance kicked in to protect his blank-slate worldview. In order to allay this dissonance, motivated reasoning stepped in to block out the information by Don ceasing to listen to it.

Following the podcast and still feeling a bit dissonant, Don then turned to YouTube where his confirmation bias persuaded him to actively search out the blank-slate hypothesis applied to gender. There, his dissonance was restored as he reinforced his currently held beliefs on the issue. Moreover, the information was readily assimilated into Don's psyche thanks to motivated reasoning.

The next day, Don then constructed an argument in favor of the blank-slate hypothesis and gender using the YouTube* videos as evidence. In my opinion, this is a great example of how a cognitive bias has lead to an individual constructing a flawed argument. In this case, the confirmation bias has lead Don to commit the cherry-picking fallacy. Note, the reason this is cherry-picking is that Don chose not to discuss the science that supports the biological determinism aspect of gender, which is not a fringe view in science. If he truly intended on being intellectually honest in the argument, he would have addressed this as well.

Since the topic of gender is rather contentious, I would like to point out that, currently, the scientific evidence points towards it being a mixed bag. In other words, what influences an individual's gender should be viewed on a spectrum with nature (i.e., biological determinism) at one end and nurture (i.e., social construct) at the other rather than viewing it as binary (i.e., one or the other). In the words of psychologist Nigel Barber [7], “The brain may not be entirely blank at birth but it is not entirely programmed either. It is an interesting mix of script and improvisation.”

Gender is undeniably complex and there are many individuals in our society that struggle with it. Just because you may find yourself not having to endure this struggle doesn't mean that others aren't. We are all collections of conscious stardust attempting to make our way through this crazy thing called life and hopefully making the most of it. Some of us have depression, have to endure economic hardships, or find difficulty with our gender identity; we all have aspects of our life that challenge us and, ultimately, want nothing more than to be loved and accepted. Please remember to be kind to one another.

*In general, YouTube videos are NOT an acceptable form of evidence. However, let's suppose that in this case they are lecture recordings from a credible University with references included.

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How to Minimize these Biases

It is unfortunate, but an undeniable truth, that cognitive biases can never be completely eliminated; however, they can be minimized. For these particular biases, as with most biases, it is important to seek out as much information as possible about the topic in an attempt to construct a holistic view. In other words, you want to make sure that you're looking at this topic from every angle in an attempt to understand the bigger picture.

What is more, it is important to seek out the science if it exists as well as multiple, credible scientific authority figures who are informed about this particular topic. These individuals act as a conduit for the information coming from the scientific community and will be able to tell you the conclusion(s) reached from all of the scientific evidence gathered to date on the topic. Instead of relying on first impressions or doing what your “gut” is telling you, it is important to take these steps before making any decisions.

1) Terry should have taken time to search out and actually watch videos that communicate the science surrounding global warming. Further, he should have sought out actual scientists who could help him to better understand how it is that scientists are so confident that humans are the cause of current warming trends. What is more, they could have helped Terry to deconstruct the most common denier arguments and expounded a bit on why they're wrong.

2) Cheryl should have made a greater effort to understand the science available. As with Terry, she should have spoken with actual scientists or her science teachers at greater depth about the methods used to pinpoint the actual age of the Earth. However, this would also require her to question her family and faith, which is very difficult to do (I know this first hand). Ultimately, Cheryl may never actually reach the truth unless she chooses to distance herself from her church and even her family as the desire to fit into your peer group, especially your family, is very strong.

3) Don did a great job looking into the blank-slate hypothesis to gender, but failed to look at the other side. Further, since Don is a college student, he should have went to his University's psychology department and talked with a number of the professors there for more information on the topic. Only by examining the full picture (i.e., social construct versus biological determinism) can Don begin to understand the full complexity of how gender identity is shaped within an individual.


Cognitive biases are a constant threat to critical thinking as they are, unfortunately, always present due to our inherently flawed minds. That said, there is still room for hope, as we've discussed here, once you have learned about the particular cognitive bias, there are steps that can be taken to minimize it. Keep in mind, as we've discussed previously, a cognitive bias is not the same as a logical fallacy.

If you find yourself being influenced by this cognitive bias, it doesn't automatically mean that the argument you subsequently construct will be bad. This does mean, however, that there is a strong possibility that the argument is not the best argument. As a Critical Thinker, you should take a moment to re-evaluate the situation/topic after you've thoroughly conducted a holistic investigation. Only then can you be confident that confirmation bias and/or motivated reasoning isn't leading you down an irrational path.


[1] Nickerson, Raymond S. (June 1998), "Confirmation Bias: A Ubiquitous Phenomenon in Many Guises", Review of General Psychology, 2 (2): 175–220

[2] Weston, Drew, et. al. Neural Bases of Motivated Reasoning: An fMRI Study of Emotional Constraints on Partisan Political Judgment in the 2004 U.S. Presidential Election. Journal of Cognitive Neuroscience (2006); Volume 18, Issue 11: 1947-1958.

[3] Freud, S. On Metapsychology: The Theory of Psychoanalysis: 'Beyond the Pleasure Principle,' ' The Ego and the Id' and Other works. Penguin; 1991.

[4] Climate change: How do we know? NASA Global Climate Change, Vital Signs of the Planet.

[5] Baterman, Paul S. How Science Figured Out the Age of Earth. Scientific American (2013).

[6] Tabula rasa - Wikipedia

[7] Barber, Nigel. The Blank Slate Controversy. How much of our individuality is determined at conception? Psychology Today (2016).