October 24, 2018 | Mark Paradies

Confirmation Bias – Can You Think It Away?

As Francis Bacon once said:

“The human understanding when it has once adopted an opinion
draws all things else to support and agree with it.”

That concept has a scientific name – Confirmation Bias.

Confirmation bias can have an impact on your root cause analysis results. If you use a system that has you develop a hypothesis and then try to prove/disprove it, you may be impacted by confirmation bias.

When you develop a hypothesis, you start to get attached to it. It becomes your opinion. You subconsciously try to prove it. Your subconscious mind guides you to cherry-pick “evidence” that confirms your belief and disregard evidence that conflicts with your belief. You only see what confirms your beliefs (your hypothesis).

Even though you realize the concept of confirmation bias, you may not be able to will yourself NOT to fall victim to it. In the book, The Little Book of Stupidity (2015), Sia Mohajer wrote:

“The confirmation bias is so fundamental to your development
and your reality that you might not even realize it is happening.”

However, some who promotes the root cause analysis techniques of Fault Trees and Cause and Effect suggested that once you understand the concept of confirmation bias, you can counteract it by purposefully looking for evidence that disproves your hypothesis.

Can this work? Yes, if you believe you can consistently overcome human nature. Personally, I doubt it and I have never seen any evidence that willing yourself to resist a subconscious inclination works.

The more firmly you hold a belief or the more right you think you are, the more difficult it is to seek and believe counterfactual evidence.

I have seen research that a complex concept called “consider the opposite” might work in jury trials:

“Ask yourself at each step whether you
would have made the same high or low
evaluations had exactly the same study
produced results on the other side of the issue.”

Could you do this consistently as you perform a root cause analysis? I have my doubts that I could.

Scott Adams demonstrated Confirmation Bias in a cartoon and wrote about trying to change your mind when confronted with counter-evidence in his blog…


So, what should you do?

My suggestion is for you to adopt a root cause analysis system that doesn’t require the development of a hypothesis.

The TapRooT® Root Cause Analysis System starts by collecting and verifying facts and organizing them into a SnapCharT®. This naturally causes the investigator to look for confirming and counterfactual evidence without putting more emphasis on either. This evidence collection and verification is a critical part of the TapRooT® investigation. It allows the root cause analysis to precede on proven facts OR at least highlights where assumptions are being made by investigators.

This eliminates confirmation bias and produces an accurate root cause analysis.

Want to learn more about the TapRooT® System? See:


Or attend one of our courses. See the upcoming course list at:



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5 Replies to “Confirmation Bias – Can You Think It Away?”

  • David Rawls says:

    This reminds me of the Pioneer Venus mission of the late 70’s. During the mission, Pioneer dropped 4 thermal probes into the Venusian atmosphere and kept one on board. All five probes showed that Venus radiates more heat into space than it receives from the Sun. In a book on this mission, NASA claimed that all five probes were in error because “Dr. Carl Sagan assures us that Venus is hot because of a runaway greenhouse effect.” NASA has made no attempt to repeat this experiment.

  • Jeffrey Van Pelt says:

    As mid-term elections approach I can see no greater illustration of Confirmation bias. No matter which side of the aisle you may reside within, you (and I) look for the evidence out there that supports our position. It is easy to turn off the “other side’s” valid points while standing firm on our won.
    Within a TapRoot investigation too often a senior leader joins the investigation and “wills” his pre-determined confirmation bias on the junior members of the team. I am not sure if in our teachings we do a good job of training facilitators on how to combat such bias.
    I am a behavioral safety specialist. I make a living of studying why a person did or did not perform a behavior (act). I believe a dedicated course on managing “rank and position” in a TapRoot investigation would be a worthwhile endeavor.

  • Harry Winkler says:

    I wish I was still teaching high school health life management. I constructed a unit entitled “How to think and determine reality” I used the concept of confirmation bias throughout the unit. I retired form high school teaching in 2009 I could not believe that the state didn’t require a unit as the one I constructed.

  • Erle Harris says:

    Human Nature says that confirmation bias is real and may predominate thought.
    God’s Nature says that He gives us permission and enables us to turn our backs on any kind of bias and replace it with His truth, which is absolute.

    • Bob Wyman says:

      And that is where the phrase (that is often misused and sometimes to one’s peril) Jesus said that his Father was the truth and the truth shall set you free. Obviously having nothing to do with modern day courtroom drama.

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