Frighten Them and They Will Believe It

How emotions increase false belief adoption

Posted Jan 12, 2020

False information spreads faster than the truth on the internet, and false information about scientific topics is among the most rapidly spread categories. What makes us prone to believing something that is utterly or even mostly incorrect? Can anything be done to counteract our acceptance of incorrect scientific information?

Let’s start with the statement “vaccines overstimulate the immune system.” This statement is false; if we struck “over” from before “stimulate” we would have a true statement. The false statement, however, is rather unimposing and matter of fact. It also relies on a technical point about immune system biology. Perhaps if you saw it on Twitter or Facebook you would glance but not commit it to memory. If you were the parent of a two month old infant and in the process of thinking about your child’s first immunizations, this bland statement might not influence you one way or the other.

Now let’s change the tone of the statement. “Every time you give your child one of the hundreds of vaccines we are told they have to have, her immune system goes wild with attack antibodies ready to destroy your baby’s health.”

The substance of this new statement is largely the same as the first one—it asserts that somehow vaccines put the human immune system into overdrive. Yet it is now filled with many emotional words. There are now “hundreds” of vaccines that we are being “told” (i.e. “coerced”) into giving our children and they make the immune system go “wild,” “attack,” and “destroy.” Perhaps this statement, unlike the first one, grabs your attention and makes you wonder if indeed you want to vaccinate your baby.

Indeed, an impressive body of research shows that raising emotions, especially fear and anger, increases the chances that a false statement will be believed, remembered, and shared. As Portia puts it in Shakespeare’s The Merchant of Venice:

I can easier teach

twenty what were good to be done, than be one of the

twenty to follow mine own teaching: the brain may

devise laws for the blood, but a hot temper leaps o’er

a cold decree. . . .

Source: Shutterstock

This is something politicians figured out long ago—don’t just tell them that some people coming into your country may have committed crimes in the past; warn them that hordes of drug dealers, rapists, and terrorists are pouring over your borders ready to murder and pillage. If possible, find a single story of one such murderous immigrant and detail what happened to his victims in gory detail. When more sensible voices come by later and point out that the denominator for this phenomenon—the total number of people who have immigrated into your country—is far larger than the numerator—the number of immigrants who commit crimes—and that for the most part immigrants have a positive effect on your society and its economy, it is already too late. The original false, highly emotional message is now impervious to such corrective, data-filled recitations

“…People base their judgements of an activity or a technology not only on what they think about it but also on how they feel about it; they use an affect heuristic,” writes Ohio State University Professor Ellen Peters, who studies the role of affect and emotions in decision-making.[1] For example, Peters explains, the terms “mad cow disease” and “bovine spongiform encephalitis (BSE)” refer to the same neurodegenerative disease, but media use of the former term elicits more fear and reduces beef consumption more than the latter.

What Determines the Things We Believe and Remember

We are bombarded with many, many more statements purporting to be factual than we can possibly incorporate into memory or on which to base decisions. Many times, we see statements about things that we have never considered before. Most likely, a young couple with a new baby did not spend much time thinking about vaccine safety until their own first baby approached two months old. Whether we notice a new statement in the media or on the internet depends in part, of course, on its relevance. The young couple is less likely to pay attention to a statement like “to prevent dementia from getting worse, you should eat more vegetables” than to one about how to prevent sudden infant death syndrome (SIDS).

Another important factor that determines what we believe and remember seems to be the novelty of a new statement. If a statement seems boring and already passé, we will ignore it. How many times can we be told “get more exercise?” That statement is absolutely true and critical for improving health and well-being, but put that way it fails to capture much attention.

If the exercise statement is couched with something that seems novel, however, we might stop and consider it. “Exercise found in recent study to extend average life-span.” We already knew that exercise is beneficial (or at least we have already been told that a million times), but here we have a brand-new piece of research that tantalizes us with the possibility of living longer. Adding a bit of novelty, even to an old message, makes it noteworthy. By the way, we made that headline up: although exercise is great, whether it extends how long one lives is dependent on a lot of factors. So please don’t cite us and pass on a misstatement!

Perhaps the most important factor that determines how much impact a statement will make on decision-making is whether it evokes strong emotions when we first encounter it. In the simplified version of how our brains work, we have two systems, one fast and one slow. The fast one, which is based in the more primitive parts of the brain like the limbic cortex, uses short-cuts to make rapid decisions and is highly susceptible to basic emotions like fear, sadness, anger, disgust, and happiness. The slow one, which is based in the more sophisticated prefrontal cortex, uses reason and experience to make rational decisions based on data. These systems have the capacity to inhibit each other; when strong emotions are stirred the limbic cortex can inhibit the prefrontal cortex and prevent us from using reason to make a decision. On the other hand, we have the capacity to muster the power of the prefrontal cortex to suppress our more primitive brain and assert reason over emotion.

This view of the brain is a well-worn story that of course obscures a huge amount of detail and nuance, but it is useful in explaining why emotions are so important in reinforcing false beliefs. When the new parents see the emotional statement about the alleged dangers of vaccines, we would hope that they would pause, ask themselves if this could possibly be true, and consider what sources might give them reliable information. We want them to ask their own pediatrician and consult the websites of reliable organizations like the American Academy of Pediatrics or the CDC. In reality, however, this couple has a million things on its mind—there are constant recommendations about how to advance the baby’s diet, she’s outgrowing her newborn clothes, people at work have stopped honoring the idea of maternity/paternity leave, emails and texts are mounting up, and the rent still has to be paid. There just isn’t time to research vaccines.

But the terrifying statement about vaccines making the immune system go berserk has made its impression on the couple. It is not easy to ignore. So, they click on a few of the comments made in the Twitter feed or Facebook page where the statement is posted and see one comment after another that confirms the original scary message. Ten, twenty, thirty people jump into the conversation, each with some frightening tidbits of information about a child supposedly harmed by a vaccine or an easily graspable (albeit incorrect) explanation of how the immune system works and how vaccines harm it. Perhaps after 15 or 30 minutes of this, the couple realizes they have other things they must do and break away, but the damage has been done. They are emotionally aroused, scared, and a bit angry that it took a session on Twitter to find out things that the medical establishment and pharmaceutical industry are supposedly hiding from them.

In the worst-case scenario, this couple, that had previously entertained no fixed opinion about vaccinations, now decides to put off the baby’s first immunizations. Their child does not get her shots to prevent potentially catastrophic, communicable diseases like diphtheria, pertussis, tetanus, H. flu type b, and polio. Moreover, after this point even if the couple encounters correct information about vaccines, the mere mention of the word “vaccine” stimulates the original emotions they felt when they first saw that Twitter message and the reasoning parts of their brains immediately shut down. Who knows if this child, subsequent children the couple may have, or some of the children of people in their social network will ever get any vaccinations?

How to Counteract Misstatements

What can we do to prevent the initial contact with misinformation from becoming a fixed belief and influencing important health-related behaviors? As individuals, we can be on guard so that whenever we see a statement that provokes an emotional reaction, we push pause and wait to calm down before evaluating it.

Working on an individual level is important, but we also we need to develop strategies with a broader reach. One possibility is to make our corrective messages just as emotionally wrought as the misinformed ones. Instead of fact-based, unemotional explanations about how vaccinations work, why they are necessary, and how safe they are—the kind of messages that medical experts and scientists feel most comfortable giving—we might try showing pictures of babies wracked with whooping cough to the point that their ribs crack, dying from measles, or succumbing to H. flu meningitis. One of us has seen and taken care of children with illnesses that are now preventable with vaccines; it just takes one experience of a baby with diphtheria having a heart attack or a young child dying within hours of developing the rash of meningococcal meningitis to become passionate about immunizations. “If you don’t vaccinate your child, he or she could die,” we might say in the spirit of stirring fear in the hearts of new parents.

A much discussed and very rigorously conducted study of this approach, however, yielded surprising findings that serve as a cautionary tale. In a randomized trial that varied the emotional content of correct information about vaccines, Dartmouth’s Brendan Nyhan and colleagues found that pictures of children sick with measles actually increased subjects’ belief in the false link between vaccines and autism. The researchers, and many others since then, speculated that this “backfire effect” occurred for much the same reason as explained above: any evocation of emotion, regardless of its content, summons memory of the original belief rather than the newly presented correct one. From this study, many have decided that counteracting emotionally driven health misinformation with emotionally driven correct information is potentially dangerous.

Since the publication of this paper nearly six years ago, some studies have replicated the Nyhan et al finding, but others have not supported the “backfire effect." Thus, whether fighting fire with fire (i.e., emotional misinformation with emotional correct information) is an effective or even safe intervention is going to require more research.

One way of counteracting false health and science information without risking a putative “backfire effect” might be to prevent it from being committed to permanent memory in the first place. The literature is replete with warnings that merely counteracting false statements with facts is an ineffective approach and that people cannot be counted on to use their analytical skills when confronted with misstatements. Yet studies are increasingly showing that neither of these is absolutely the case and that people can be encouraged to use analytical thinking to make decisions, even with regard to controversial topics. In fact, findings suggest that it is precisely leaving false statements uncorrected that leads to their being nearly impossible to dislodge later on. “Therefore, media and policymakers should ensure that the coverage of misinformation at no point presents itself without corrective information,” assert psychologists Man-pui Sally Chan, Christopher Jones, and Dolores Albarracin.[2]  “Uncorrected repetition of misinformation opens the opportunity to generate thoughts in agreement with it.”

The Elements of Counteracting Misinformation

The critical elements to help ensure that corrective information works seem to involve at least three things. First, corrections should be made as close in time as possible to misstatements. Second, corrections should appear on the same platform as the misstatements. Third, corrections should be clear, understandable, and appeal to the values of the audience.

We know from abundant basic and clinical neuroscience that short-term memories are malleable but become much less so when transferred to long-term memory storage. We also know that “place” plays an important part in memory—where we saw or experienced something is an important way in which memories are stored and retrieved. From this information, it seems probable—but still to be tested—that our first two assertions are accurate: to successfully counteract a misstatement, place the correct information close to it in both time and place. That means, therefore, we should try to get our scientific statements directly onto the Twitter feeds, Facebook group pages, and other social media platforms and websites as soon as misstatements appear on them.

The third proposed basic element for counteracting misinformation is less easily justified. The literature on the form that corrective information should take is too long to review here, but much of it is laboratory based and it is therefore unclear what will really work in the field. Although it is clear that strong emotion fosters memory, including memory of false statements, we will begin by steering clear of trying to evoke fear and anger in case the backfire effect is a real phenomenon. Rather, we hope to focus on people like our prototypical couple who has just read the frightening message about vaccine safety just as they are about to decide on whether to vaccinate their new child. With that couple in mind, we will approach counteracting messages by trying to establish common interests, inquiring about what the people already know about the topic, and gently introducing facts in ways that are understandable but not overly simplified.

Is it necessary to scare people in order to get them to shun false statements and adopt healthy behavior? Or does that backfire and make them even more recalcitrant to scientific consensus? We know quite a lot about this from laboratory studies. Now it’s time to find out what works on everyone’s favorite social media platform.


[1] Peters E: Overcoming innumeracy and the use of heuristics when communicating science. In Jamieson K, Kahan D, Scheufele DA eds, The Oxford Handbook of the Science of Science Communication. New York, Oxford University Press, 2017, p. 392

[2] Chan M, Jones C, Albarrach D: Countering false beliefs: an analysis of the evidence and recommendations of best practices for the retraction and correction of scientific misinformation. In Jamieson et al, Ibid. p. 346.