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Here’s What Happens in the Brain When You’re Presented with Counter-Evidence

A recent study tries to delineate what goes on in the brain when political beliefs get challenged
January 25, 2018 | Comments

Over the course of the past month, we’ve been thinking a lot about why people don’t change their minds and what to do about it. We have actually been thinking about this problem for a few years, but in the past month in the course of some very rich conversations with people we’ve met at various speaking engagements and conferences, we’ve been challenged to think about it some more. We are particularly preoccupied now with finding solutions. This is of course a difficult problem and we would love to hear from all of you about ideas you have on how to change people’s minds.

In the meantime, we wanted to share some recently published research that gives us more insight into what goes on when people can’t change their minds. Under what conditions are people more willing to change their minds and what exactly is going on in their brains when they can’t? A relatively recent, very well-designed study published in Nature looked at these questions and found some fascinating results. Below is a deep dive into the research findings. As part of our mission at Critica, we’re dedicated to making complex science more accessible to everyone. We hope this write-up of a relatively complex and very technical study helps expand your understanding of the fascinating and difficult challenges of changing people’s minds many of us find ourselves facing increasingly these days.

Why people hold onto political beliefs in the face of counter-evidence

This study, published in 2016, looked at how our brains respond when we’re faced with counter-evidence about beliefs we hold firmly. The impetus for the study was the recognition that while it’s well-known that people resist changing their minds, especially when the beliefs being challenged are particularly important to us, not much is known about what brain processes actually govern this phenomenon. We have an intuitive understanding of the fact that we tend to “rationalize” our beliefs and become defensive when they are challenged, but while it seems clear that being faced with counter-evidence is likely to cause us to feel negative emotions, it’s not entirely clear what that looks like in the brain under these particular circumstances. This study set out to map out this process that we understand pretty well on an intuitive and psychological level in the structures of the brain itself.

Study Design & Methods

In order to replicate real situations in which we are faced with challenges to our beliefs and control for a number of potential interfering factors, the researchers designed a balanced and intricate study. Potential participants were recruited from the Los Angeles area. Participants were given a pre-screening questionnaire asking to rate how “political” they consider themselves to be on a scale from 1 to 5, with 5 being very political. Only participants with a score of 4 or higher were included in the study to ensure that political beliefs would be important to participants. Potential participants were then asked how they identified politically on a scale of 1 to 7, with 1 being very liberal and 7 being very conservative and were included only if they responded with a 1 or 2 to control for any potential systematic differences according to political leaning that might interfere with the results of the study. Participants were then given a series of political and non-political statements and asked to rate their level of agreement with them. After all of these screening processes, forty people were deemed eligible and included in the study.

In the study itself, participants read 8 political statements and 8 non-political statements, with all of which they had indicated before the study started that they agreed strongly. Political statements were statements such as “Abortion should be legal” or “taxes on the wealthy should be increased,” while non-political statements were more factually-oriented and often historical, such as “Thomas Edison invented the lightbulb.” After reading the statement, the participants were presented with 5 counter-arguments and then presented with the original statement again.

Participants were asked to rate their level of belief in the original statement again after being presented with the counter-argument challenges. At the same time, participants underwent fMRI scans in order to detect brain activity before, during, and after challenges were presented to both political and non-political beliefs. Participants were also followed up several weeks later by phone and asked to rate the degree to which they believed in both political and non-political statements that had been challenged during the experiment.


Some of the results of this study were unsurprising; others were very intriguing. The results are complex so we will go through each one in turn.

  • People were more willing to change non-political beliefs. This is relatively unsurprising. In surveys collected at the end of the study and again several weeks later, people were more likely to have changed non-political beliefs than political beliefs in response to “counter-evidence.” In fact, political beliefs hardly changed at all. This is not surprising given what we know about how strongly people feel about politics.
  • Political counter-evidence challenges stimulated parts of the brain associated with self-reflection and memory. This result is somewhat intuitive, but this has not been confirmed in brain imaging studies before. Essentially, when confronted with challenges to strongly held beliefs, in this case political beliefs, it would seem that people have a tendency to turn inward and scan their memories to assess their beliefs and self-identities, and all of this is reflected in the brain activity measured in this study. The parts of the brain stimulated when people were faced with challenges to their political beliefs a group of brain regions called the default network of that are associated with reflection on self, identity, and memory. In contrast, when faced with challenges to non-political beliefs, there was a lot more activity in the prefrontal cortex, the part of the brain associated with reasoning and complex thinking, that would suggest more active engagement with the content of the counterarguments.
  • Individual differences in willingness to change opinion were associated with differential activation of parts of the brain associated with emotion. The researchers in this study were not just interested in what happens in the brain, on average, when people are confronted with compelling counter-evidence and don’t change their minds, but they also wanted to know what differentiates the brain response of someone who refuses to change their opinion from someone who’s willing to change. Again, what they found seems somewhat intuitive but represents an important finding for our understanding of these issues. Since almost no one changed their minds in the political belief scenario, the researchers used differences in degree of opinion change in the non-political belief scenario to look at differential activity in the brain. What they found was that people who did not change their minds showed more activation in the amygdala and anterior insular cortex, parts of the brain associated with emotion regulation and the response to threat, when confronted with counter-arguments. Again, this is not entirely unsurprising, but it does suggest that people who feel emotional about a particular issue will have greater activation of threat-related portions of their brain and suppressed activation of reasoning portions of their brain when faced with counter-arguments.

Implications & Limitations

As with any study, this study had a few key limitations that should prevent us from exaggerating the importance of its findings. The authors themselves note that the distinction between political and non-political beliefs may not be a clear cut as desired. For example, because political beliefs are likely something we care more about than non-political beliefs, especially in a group of people selected for being highly interested in politics, the contrast may really be one of salience. That is, the subjects may just have cared more about the political beliefs than about the non-political ones. As well, the subjects included in this study were all liberal politically, so that the results may not apply to more conservative thinkers.

Like any complicated brain imaging study, this one required a great deal of data analysis to separate artifact from true signal. As such, until it is replicated its conclusion must be seen as preliminary. One area of concern that the authors note, for example, is that the differences in amygdala and anterior insula activity were not seen when comparing the response of political to non-political counter-arguments but only in a correlational analysis of individual differences in belief change. The researchers offer several explanations for why this is so, but it somewhat weakens confidence in the finding.

Despite these limitations, this study may have some interesting implications. When faced with evidence that contradicts firmly held beliefs, people withdraw inward, examining themselves rather than the evidence being provided. Furthermore, counter-evidence appears to provoke threat-related parts of the brain, thus forcing some people toward resisting it. Our brains appear to do what they can to insulate us from new evidence and changing our minds.

Normally we would use evidence-based arguments to convince someone that their viewpoint is incorrect. Yet it seems that this might only not work, it may even backfire. As a result, our first step should really always be to understand what kind of position or opinion this is. Is the person very passionate about it? Did he or she form this opinion because of some personal, emotional experience? Is holding this opinion very important to this person’s identity? Asking questions about how and why the person formed the opinion might give you some clues as to what the right approach to gently nudging them toward a more evidence-based view might be.

If you find that a position or opinion is incredibly emotionally salient or that it forms an important part of the person’s identity, then you have to take a different tactic. We’ve written in various outlets more extensively about some of the ways to do that, but some of those tactics include things like motivational interviewing approaches and using examples of influential people in that person’s social circles who espouse the correct point of view to help them feel more comfortable with the change.

These kinds of methods of persuasion take longer to enact, but as we have seen, in some cases this is your only option. Certainly presenting reasoned counter-arguments is not always the right approach. No matter what, we must always approach these kinds of conversations in a thoughtful, empathic way if we stand any chance of changing people’s minds.

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