Confirmation Bias: Why People Deny Facts and How to Reach Them 

Why do people cling to a belief even when the facts say otherwise? Confirmation bias – the tendency to search for, interpret and recall information in a way that confirms what we already believe – is a big part of why people deny facts. People will even give up money to avoid hearing the other side. For healthcare marketers, that matters: patients and HCPs who already think they know the answer may tune out the very evidence meant to persuade them. 

Key takeaways 

• Nearly two-thirds of people in one study gave up money to avoid opposing arguments. 

• Correcting a vaccine myth reduced false beliefs – but lowered intent to vaccinate among the most sceptical parents. 

• In Singapore, people who distrusted official sources often trusted family and friends instead. 

• Facts rarely backfire, but facts alone seldom change deeper attitudes. 

What Is Confirmation Bias? 

Confirmation bias is the tendency to search for, interpret and recall information in a way that confirms one’s pre-existing beliefs. It explains why the same evidence can strengthen two opposing views at once – and why existing preferences are so hard to shift (see why consumers liking your brand is not enough). 

Why Do People Avoid Facts That Challenge Their Beliefs? 

Because exposure to opposing views feels costly – so costly that people will pay to avoid it. Professor Jeremy Frimer of the University of Winnipeg and colleagues offered 200 Americans on both sides of a divisive social issue a lottery entry for $10 if they read eight arguments against their position, or $7 if they read eight arguments supporting it. Nearly two-thirds of both groups gave up the chance of winning extra money to avoid the opposing view¹. 

Across five studies covering contested topics such as elections, climate change and guns – and, as a comparison, non-political preferences like Coke versus Pepsi – people avoided opposing arguments at similar rates whichever side they were on, but showed no such avoidance for the non-political questions¹. It looks like a deliberate, if often unconscious, way of protecting a belief. 

Does Confirmation Bias Affect Health Decisions? 

Yes – the same instinct shapes how patients respond to health information. 

• Context: a randomised trial with 1,759 US parents on encouraging MMR vaccination. 

• Intervention: factual corrections debunking the discredited link between the MMR vaccine and autism. 

• Result: the corrections reduced the false belief, but among parents with the least favourable views of vaccines, they reduced stated intent to vaccinate². 

• Limitation: the study measured intentions, not actual vaccination. 

• Lesson for practice: being shown they were wrong didn’t change sceptical parents’ underlying position – if anything, it hardened it. 

How Does Confirmation Bias Play Out in Asia-Pacific? 

• Context: a nationally representative survey of 6,094 Singaporeans aged 56 to 75, in 2020 and 2021. 

• Finding: trust in formal sources such as government predicted COVID-19 vaccination, but a subgroup with low trust in official sources placed high trust in informal networks – family, friends and community³. 

• Limitation: a survey shows association, not cause. 

• Lesson for practice: for people who distrust the official channel, more messaging from that channel is unlikely to help; the researchers suggested working through the networks people already trust. 

Planning communications for a sceptical audience? DeltaMV’s Healthcare Behavioural Strategy team can help you design messages that get past confirmation bias. 

Do Facts Still Work? 

Yes, at least on the facts themselves. A large replication effort testing corrections against dozens of misperceptions found that outright backfire – where a correction makes someone believe a false claim more strongly – is rare; most people update their factual beliefs at least somewhat⁴. The lesson isn’t that facts don’t work; it’s that facts alone often aren’t enough to change the attitude or behaviour behind them. 

How to Get Past Confirmation Bias: 4 Steps 

1. Lead with what the audience already values, not with a correction of what they got wrong. 

2. Choose a trusted messenger – peers, community voices or the HCP a patient already trusts. 

3. Pair facts with emotion – move beyond straight facts to the hearts and minds of the audience. 

4. Design the channel around trust – see why human insight is key to pharma omnichannel success and our introduction to nudges and choice architecture. 

What Are the Limitations of the Evidence? 

• Settings differ: the MMR trial was in the US and the Singapore study focused on older adults. 

• Intentions aren’t behaviour: several findings rely on what people say, not what they do. 

Frequently Asked Questions 

Why do people deny facts? 

Largely because of confirmation bias: people seek and accept information that fits what they already believe, and avoid information that challenges it. 

Does correcting misinformation backfire? 

Rarely on the facts themselves, but corrections can fail to change – or even harden – attitudes among people with strong prior beliefs. 

Next Steps: Build Messaging People Actually Engage With 

A patient or HCP with a strong prior belief – about a treatment class, a competitor or a public health measure – is unlikely to be moved by facts and figures alone. Reaching them means pairing accurate information with trusted messengers, relatable framing and communication built around what the audience already values. 

Want patient and HCP communications that get past confirmation bias instead of triggering it? Get in touch with DeltaMV’s Healthcare Behavioural Strategy team. 

References 

1. Frimer, J. A., Skitka, L. J., & Motyl, M. (2017). Liberals and conservatives are similarly motivated to avoid exposure to one another’s opinions. Journal of Experimental Social Psychology, 72, 1–12. https://doi.org/10.1016/j.jesp.2017.04.003 

2. Nyhan, B., Reifler, J., Richey, S., & Freed, G. L. (2014). Effective messages in vaccine promotion: A randomized trial. Pediatrics, 133(4), e835–e842. https://doi.org/10.1542/peds.2013-2365 

3. Tan, M., Straughan, P. T., & Cheong, G. (2022). Information trust and COVID-19 vaccine hesitancy amongst middle-aged and older adults in Singapore: A latent class analysis approach. Social Science & Medicine, 296, Article 114767. https://doi.org/10.1016/j.socscimed.2022.114767 

4. Wood, T., & Porter, E. (2019). The elusive backfire effect: Mass attitudes’ steadfast factual adherence. Political Behavior, 41(1), 135–163. https://doi.org/10.1007/s11109-018-9443-y