Confirmation Bias

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This post, my inaugural entry to deal with one of the many specifics of “Proper Thinking,” will be devoted to Confirmation Bias. With regards to the How, Why and What of thinking, this falls into  Howhonestly acknowledging a barrier to proper thinking in order to adapt and refine our adventuring path towards the pursuit of Truth.

The human understanding when it has once adopted an opinion (either as being the received opinion or as being agreeable to itself) draws all things else to support and agree with it. And though there be a greater number and weight of instances to be found on the other side, yet these it either neglects and despises, or else by some distinction sets aside and rejects, in order that by this great and pernicious predetermination the authority of its former conclusions may remain inviolate

– Francis Bacon, Novum Organon (1620)

What is it?

Confirmation Bias is a cognitive bias that affects every living human, regardless of their level of intelligence.  It’s a self-deception, whether conscious or unconscious.  It can manifests itself in several ways:  Searching, Interpreting, Maintaining and Recalling of information and evidence.  It is definitely a barrier to truth and accurate thinking.


It’s the tendency for a person to focus their attention and search/select information that confirms their beliefs – rather than opposes.  You avoid or ignore evidence that is contradictory to your beliefs.  Once you’re satisfied you’ve found enough confirming evidence, you stop searching.


The tendency for a person to interpret (twist) evidence in a way to confirm their beliefs and prove the opposition wrong.  This may involve:

  • Overvalue supporting information and underrate the importance of contradictory information.
  • Going out of your way to disproportionately analyze opposing evidence for shortcomings (undermining evidence) – an action you don’t take for your confirming information.
  • Hold opposing information to a much higher standard than confirming evidence (Disconfirmation Bias). This can lead you to believe you’re doing a thorough job of looking at all sides of an argument – but you’re just fooling yourself.
  • In politics particularly, identical evidence can, and is, interpreted to support each of the opposing party’s disparate beliefs.


The tendency for a person to maintain their preexisting beliefs, despite contradictory or disconfirming information. Frequently the evidence that invalidates or eradicates their beliefs often increases the intensity of their personal beliefs (a defensive reaction: rationalization and/or denial).  


Individuals tend to recall memories which confirm their thoughts and feelings – rather than oppose.

Essentially, Confirmation Bias is all about defending your beliefs at all costs. It’s stronger for emotionally charged issues and deeply entrenched beliefs such as politics and religion; beliefs which are base upon prejudice, faith or tradition rather than on empirical evidence.

The crux of the issue is that we’re wholeheartedly blind to our susceptibility to this bias.

Why do we do it?

Quite simply . . . . we don’t want to be wrong, or feel negative emotions. We also want to protect our self image.

Defend our beliefs
None of us like to be wrong about anything.  We don’t want to feel duped – particularly the longer we have an invested interest (ownership) in a set of beliefs. The more we are committed and ingrained, the more we hold them dear and want to protect them. We end up with an overconfidence – as well as never thinking to question the source or veracity of why we believe what we believe.

Eliminate dissonance (negative emotions)
We have a natural desire to avoid and reject contradictions which cause Cognitive Dissonance (another closely related bias).  Cognitive Dissonance can cause us to feel like a duped fool.  We don’t want to feel this way, so we look for comfort by seeking out safe havens for our ideology.

Protect our self-image and identity
Ingrained beliefs are intertwined with our self-image. We want to avoid damaging ourselves, so we avoid situations that will harm those beliefs.

How do we fight it?

First and foremost: Acknowledge it.

Accept the fact you indeed are susceptible to this particular bias; everyone is.  Failure to do so means you’ll be cruising through life spouting beliefs that lack validity (and looking like a fool to those who may have made a legitimate effort and are better informed).  Biases are part of our psychological make-up. Make a sincere effort to recognize and acknowledge them.

Understand what we “know” is probably wrong or at best, mis- or under-informed.  Be humble.  Admit that much of what we learn throughout life is heavily influenced by the authorities who teach us. These authorities (parents, teachers, pastors, politicians, pundits, media) are all human and subject to all the same prejudices and biases as everyone.  There’s no law or guarantee in the universe that states everything they tell us is a fact or truth. In fact, some will intentionally pass information on to us to derive a certain reaction or belief – whether valid or not. [More on that in another post.]

Face the dissonance of being wrong. Question everything (at least the important stuff). Question “how” you know something or “why” you know something. What supports your current assumptions/beliefs?

Decide for yourself that you want to form accurate beliefs – based on a valid array of gathered information from all sides of an argument. Actively pursue the truth, even if it flies in the face of the status quo. Develop an attitude of “Hey, give me anything that shows my current assumptions are wrong!”  Take it on.  Accept the challenge with integrity.  Refine, refine, refine.

It isn’t easy.  We have to make a concerted effort to mobilize mental energy.  We need to embrace intellectual integrity.  We have to step back and tell ourselves we really need to rationally consider all sides of an argument or topic.  Identify your presiding belief on the subject, and decide that you need to question its validity. Try to prove it wrong.

In the world of science (if done correctly) you move closer to the truth by seeking evidence to the contrary.  There are processes and guidelines put into place to eliminate bias; things like double-blind controls, falsifiability, repeatable experiments and peer review.  Hypotheses should be discarded or modified if objections or evidence are valid.  However, just because a scientist says something, even with lots of evidence, that doesn’t mean we cannot question the experiments and data.

In science (if not done properly), you move away from the truth – and anyone taking that science as gospel will unknowingly be relying on false premises.  Issues in science can include:

  • selectively accepting/interpreting/reporting data
  • ignoring anomalies that don’t fit the experimenter’s preconceived bias
  • reliance on positive-only tests
  • blinded influence of the existing paradigm due to the academic power-structure & senior authority (tenure)
  • fear of ostracization and job security if challenging an existing academic paradigm or power-structure
  • pressure/influence from the source of funding to achieve certain results
  • or even outright fraud

Confirmation Bias is everywhere.  It can be found in politics, religion, social issues/opinions, and science.  Be particular astute to notice that “punditry” is the worst transgressor.  Talk show personalities whether on radio, television or the web present “news” and information that is entirely built on bias. They provide fuel for unquestioning followers’ pre-existing beliefs. It’s pre-filtered information matched to an already strongly biased world-view. They are watched for confirmation purposes only – regardless of whether any of what they present is accurately vetted or even determined to be the truth.

Bottom Line . . .

Don’t be a blind sheep. Question not only the information being given to you, but also the motives of those passing it on to you (For what purpose? To whose benefit?).

The ultimate goal? Screw our beliefs; we must get to the truth!

(Featured image by Ron Mader on flickr, licensed by CC BY-SA 2.0)

Some decent online sources: (there are many others of course)

As with any sourcing on the internet, links can go ‘dead’ after a time. If you find the above-mentioned links no longer working, try the WayBack Machine:    It’s sometimes a good way to pull up and view websites that are no longer active.