Removing the horse blinders: Confirmation bias

horse blinders

When it comes to evaluating new information, biases can act like horse blinders. In other words, biases can change the way you interpret or see the world.

Everyone is prone to biases, and I don’t pretend to be immune to them. But, in my opinion, if we acknowledge them head-on we may be able to counter some of their influence on us.

What is bias?

Bias is defined as a “cause to feel or show inclination or prejudice for or against someone or something”. Another way to look at bias is that it will disproportionately make you for or against something, even before knowing anything about it.

It’s important to note that biases are not always intentional. They can be formed by many mechanisms: past experiences, taught by someone else, or just plain human nature.

This is the first in a series of posts on biases designed to help people interpret information more objectively.

This first post will tackle confirmation bias.

Confirmation bias – What is it?

We all like being right. You can say whatever you want to the contrary, but it’s just human nature to want to be right. Confirmation bias, in a nutshell, is when you are more likely to trust something that confirms your beliefs.

The most common ways that confirmation bias will manifest are:
– Ignoring or downplaying anything that conflicts with your belief/opinion
– Overestimating the strength of evidence that supports your belief/opinion

A timely example would be the spread of COVID-19 vaccine misinformation. I can’t count how many times I’ve seen people say that “there is no evidence to show COVID-19 vaccines work”. Anyone who’s read my prior post should be able to tell you this is false.

But how does this happen? It’s the reasons I explained above. 1) ignoring the very well designed studies that clearly demonstrate that the vaccines work; and 2) putting way too much value towards uninformed opinions shared by those spreading misinformation (because it helps confirm a preconceived opinion on vaccines).

Social media echo chambers are a type of confirmation bias

A 2016 study reinforces the notion that social media tends to create echo chambers. This means that people will tend to only congregate into groups of like-minded individuals (and ignore others). This study also demonstrated that those who already believe in conspiracy theories were much more likely to interact with posts that were deliberately false than with posts that cite scientific evidence and debunk their beliefs. In fact, less than 1.3% of conspiracy theory believers interacted with posts that contained evidence that debunked conspiracy theories.

When you also consider that social media algorithms will recommend posts based on how you interact with them, it’s easy to see how echo chambers can form in the conspiracy theory community. Eventually, all they see are posts that confirm their beliefs.

Not just for conspiracy theorists

It’s important to clearly state that this type of bias affects us all. We are biologically hardwired to want to find facts to support what we believe to be true. Even doctors have been shown to be more likely to try to confirm an initial diagnosis rather than try to disprove it.

The COVID-19 pandemic has been a clear example of how confirmation bias can affect doctors. Early in the pandemic, hydroxychloroquine was touted as a potential treatment for COVID-19 (based on in-vitro studies). Preliminary studies suggested a potential benefit, but a majority in the scientific community remained skeptical. However, certain individuals who had bought into hydroxychloroquine were “sold” on its apparent effectiveness. But, once well designed studies showed no benefit (and even a potential for harm), some of the proponents of hydroxychloroquine lashed out at anyone who challenged their beliefs. Sadly, there are still some who believe that it works, despite the mountain of evidence that it doesn’t.

How can we counter confirmation bias? 5 tips to help counter the effects of confirmation bias:

Don’t be afraid to listen to different views

Just to be clear, I am not saying that all opinions are equal. However, it’s important to be exposed to different opinions to at least try to judge the merit of the argument that contradicts your beliefs.

Check before sharing something on social media

At the very least, read what you are sharing. But optimally you should at least do a quick google search of reputable sites to see if what you are sharing is actually supported by facts. If there is less misinformation being shared, it’s less likely to influence those who are apt to believe it.

Force yourself to try to disprove your opinions/beliefs

This is a really tough one. Many people almost identify with their beliefs to the point that if they are taken away they feel like you are taking away their passport or their identity as a person.

But it’s important to at least try. At least when you are doing it to yourself, it’s less likely to trigger you into rage-smashing your keyboard.

If debating a friend/acquaintance, be polite and respectful

I admit, I have not been very good at this at times. I’m really trying, but I have slipped and lost my patience.

But, if we want to get past this epidemic of polarization, we need to be able to talk to people who disagree with us. As an example, during the last federal election I made a concerted effort to talk politics with a friend who supported a different political party than I did. I aimed to actually listen to his points, take time to have a civilized discussion, and to always be polite.

What I discovered was surprising; I actually enjoyed our discussions more than any I had with like-minded people. So, get out of your comfort zone!

If the other people can’t be polite, then just end the conversation and move on with your day.

Try to not jump to a conclusion too early

Once you make a preliminary conclusion, you will be more likely to try to support it (even subconsciously). So, try to gather information without reaching any early conclusions.


We’re all human, so no one is immune to confirmation bias. However, I think that if we can face it head-on we can at least counter some of its effects on our beliefs.

So: get out of your comfort zone, research before sharing, try to disprove yourself, debate people with differing viewpoints (respectfully), and try not to jump to any early conclusions.

If you want a great book to read, consider reading Freakonomics. I really enjoyed this book; it’s an excellent exercise in challenging conventional wisdom, and essentially tries to disprove many beliefs (no matter how uncomfortable it may be).

*Disclaimer: contains a sponsored link (at no extra cost to you)

Dan Landry

Daniel (Dan) Landry, founder of, is an infectious diseases pharmacist at the Dr-Georges-L.-Dumont University Hospital Centre in Moncton, NB, Canada.

Recent Posts