Why Your Brain Falls for Misinformation – And How to Avoid It

Understanding the vulnerabilities of our own brains can help us guard against fake news.
This article is part of the magazine, "The Future of Science In America: The Election Issue," co-published by LeapsMag, the Aspen Institute Science & Society Program, and GOOD.
Whenever you hear something repeated, it feels more true. In other words, repetition makes any statement seem more accurate. So anything you hear again will resonate more each time it's said.
Do you see what I did there? Each of the three sentences above conveyed the same message. Yet each time you read the next sentence, it felt more and more true. Cognitive neuroscientists and behavioral economists like myself call this the "illusory truth effect."
Go back and recall your experience reading the first sentence. It probably felt strange and disconcerting, perhaps with a note of resistance, as in "I don't believe things more if they're repeated!"
Reading the second sentence did not inspire such a strong reaction. Your reaction to the third sentence was tame by comparison.
Why? Because of a phenomenon called "cognitive fluency," meaning how easily we process information. Much of our vulnerability to deception in all areas of life—including to fake news and misinformation—revolves around cognitive fluency in one way or another. And unfortunately, such misinformation can swing major elections.
The Lazy Brain
Our brains are lazy. The more effort it takes to process information, the more uncomfortable we feel about it and the more we dislike and distrust it.
By contrast, the more we like certain data and are comfortable with it, the more we feel that it's accurate. This intuitive feeling in our gut is what we use to judge what's true and false.
Yet no matter how often you heard that you should trust your gut and follow your intuition, that advice is wrong. You should not trust your gut when evaluating information where you don't have expert-level knowledge, at least when you don't want to screw up. Structured information gathering and decision-making processes help us avoid the numerous errors we make when we follow our intuition. And even experts can make serious errors when they don't rely on such decision aids.
These mistakes happen due to mental errors that scholars call "cognitive biases." The illusory truth effect is one of these mental blindspots; there are over 100 altogether. These mental blindspots impact all areas of our life, from health and politics to relationships and even shopping.
We pay the most attention to whatever we find most emotionally salient in our environment, as that's the information easiest for us to process.
The Maladapted Brain
Why do we have so many cognitive biases? It turns out that our intuitive judgments—our gut reactions, our instincts, whatever you call them—aren't adapted for the modern environment. They evolved from the ancestral savanna environment, when we lived in small tribes of 15–150 people and spent our time hunting and foraging.
It's not a surprise, when you think about it. Evolution works on time scales of many thousands of years; our modern informational environment has been around for only a couple of decades, with the rise of the internet and social media.
Unfortunately, that means we're using brains adapted for the primitive conditions of hunting and foraging to judge information and make decisions in a very different world. In the ancestral environment, we had to make quick snap judgments in order to survive, thrive, and reproduce; we're the descendants of those who did so most effectively.
In the modern environment, we can take our time to make much better judgments by using structured evaluation processes to protect yourself from cognitive biases. We have to train our minds to go against our intuitions if we want to figure out the truth and avoid falling for misinformation.
Yet it feels very counterintuitive to do so. Again, not a surprise: by definition, you have to go against your intuitions. It's not easy, but it's truly the only path if you don't want to be vulnerable to fake news.
The Danger of Cognitive Fluency and Illusory Truth
We already make plenty of mistakes by ourselves, without outside intervention. It's especially difficult to protect ourselves against those who know how to manipulate us. Unfortunately, the purveyors of misinformation excel at exploiting our cognitive biases to get us to buy into fake news.
Consider the illusory truth effect. Our vulnerability to it stems from how our brain processes novel stimuli. The first time we hear something new to us, it's difficult to process mentally. It has to integrate with our existing knowledge framework, and we have to build new neural pathways to make that happen. Doing so feels uncomfortable for our lazy brain, so the statement that we heard seems difficult to swallow to us.
The next time we hear that same thing, our mind doesn't have to build new pathways. It just has to go down the same ones it built earlier. Granted, those pathways are little more than trails, newly laid down and barely used. It's hard to travel down that newly established neural path, but much easier than when your brain had to lay down that trail. As a result, the statement is somewhat easier to swallow.
Each repetition widens and deepens the trail. Each time you hear the same thing, it feels more true, comfortable, and intuitive.
Does it work for information that seems very unlikely? Science says yes! Researchers found that the illusory truth effect applies strongly to implausible as well as plausible statements.
What about if you know better? Surely prior knowledge prevents this illusory truth! Unfortunately not: even if you know better, research shows you're still vulnerable to this cognitive bias, though less than those who don't have prior knowledge.
Sadly, people who are predisposed to more elaborate and sophisticated thinking—likely you, if you're reading the article—are more likely to fall for the illusory truth effect. And guess what: more sophisticated thinkers are also likelier than less sophisticated ones to fall for the cognitive bias known as the bias blind spot, where you ignore your own cognitive biases. So if you think that cognitive biases such as the illusory truth effect don't apply to you, you're likely deluding yourself.
That's why the purveyors of misinformation rely on repeating the same thing over and over and over and over again. They know that despite fact-checking, their repetition will sway people, even some of those who think they're invulnerable. In fact, believing that you're invulnerable will make you more likely to fall for this and other cognitive biases, since you won't be taking the steps necessary to address them.
Other Important Cognitive Biases
What are some other cognitive biases you need to beware? If you've heard of any cognitive biases, you've likely heard of the "confirmation bias." That refers to our tendency to look for and interpret information in ways that conform to our prior beliefs, intuitions, feelings, desires, and preferences, as opposed to the facts.
Again, cognitive fluency deserves blame. It's much easier to build neural pathways to information that we already possess, especially that around which we have strong emotions; it's much more difficult to break well-established neural pathways if we need to change our mind based on new information. Consequently, we instead look for information that's easy to accept, that which fits our prior beliefs. In turn, we ignore and even actively reject information that doesn't fit our beliefs.
Moreover, the more educated we are, the more likely we are to engage in such active rejection. After all, our smarts give us more ways of arguing against new information that counters our beliefs. That's why research demonstrates that the more educated you are, the more polarized your beliefs will be around scientific issues that have religious or political value overtones, such as stem cell research, human evolution, and climate change. Where might you be letting your smarts get in the way of the facts?
Our minds like to interpret the world through stories, meaning explanatory narratives that link cause and effect in a clear and simple manner. Such stories are a balm to our cognitive fluency, as our mind constantly looks for patterns that explain the world around us in an easy-to-process manner. That leads to the "narrative fallacy," where we fall for convincing-sounding narratives regardless of the facts, especially if the story fits our predispositions and our emotions.
You ever wonder why politicians tell so many stories? What about the advertisements you see on TV or video advertisements on websites, which tell very quick visual stories? How about salespeople or fundraisers? Sure, sometimes they cite statistics and scientific reports, but they spend much, much more time telling stories: simple, clear, compelling narratives that seem to make sense and tug at our heartstrings.
Now, here's something that's actually true: the world doesn't make sense. The world is not simple, clear, and compelling. The world is complex, confusing, and contradictory. Beware of simple stories! Look for complex, confusing, and contradictory scientific reports and high-quality statistics: they're much more likely to contain the truth than the easy-to-process stories.
Another big problem that comes from cognitive fluency: the "attentional bias." We pay the most attention to whatever we find most emotionally salient in our environment, as that's the information easiest for us to process. Most often, such stimuli are negative; we feel a lesser but real attentional bias to positive information.
That's why fear, anger, and resentment represent such powerful tools of misinformers. They know that people will focus on and feel more swayed by emotionally salient negative stimuli, so be suspicious of negative, emotionally laden data.
You should be especially wary of such information in the form of stories framed to fit your preconceptions and repeated. That's because cognitive biases build on top of each other. You need to learn about the most dangerous ones for evaluating reality clearly and making wise decisions, and watch out for them when you consume news, and in other life areas where you don't want to make poor choices.
Fixing Our Brains
Unfortunately, knowledge only weakly protects us from cognitive biases; it's important, but far from sufficient, as the study I cited earlier on the illusory truth effect reveals.
What can we do?
The easiest decision aid is a personal commitment to twelve truth-oriented behaviors called the Pro-Truth Pledge, which you can make by signing the pledge at ProTruthPledge.org. All of these behaviors stem from cognitive neuroscience and behavioral economics research in the field called debiasing, which refers to counterintuitive, uncomfortable, but effective strategies to protect yourself from cognitive biases.
What are these behaviors? The first four relate to you being truthful yourself, under the category "share truth." They're the most important for avoiding falling for cognitive biases when you share information:
Share truth
- Verify: fact-check information to confirm it is true before accepting and sharing it
- Balance: share the whole truth, even if some aspects do not support my opinion
- Cite: share my sources so that others can verify my information
- Clarify: distinguish between my opinion and the facts
The second set of four are about how you can best "honor truth" to protect yourself from cognitive biases in discussions with others:
Honor truth
- Acknowledge: when others share true information, even when we disagree otherwise
- Reevaluate: if my information is challenged, retract it if I cannot verify it
- Defend: defend others when they come under attack for sharing true information, even when we disagree otherwise
- Align: align my opinions and my actions with true information
The last four, under the category "encourage truth," promote broader patterns of truth-telling in our society by providing incentives for truth-telling and disincentives for deception:
Encourage truth
- Fix: ask people to retract information that reliable sources have disproved even if they are my allies
- Educate: compassionately inform those around me to stop using unreliable sources even if these sources support my opinion
- Defer: recognize the opinions of experts as more likely to be accurate when the facts are disputed
- Celebrate: those who retract incorrect statements and update their beliefs toward the truth
Peer-reviewed research has shown that taking the Pro-Truth Pledge is effective for changing people's behavior to be more truthful, both in their own statements and in interactions with others. I hope you choose to join the many thousands of ordinary citizens—and over 1,000 politicians and officials—who committed to this decision aid, as opposed to going with their gut.
[Adapted from: Dr. Gleb Tsipursky and Tim Ward, Pro Truth: A Practical Plan for Putting Truth Back Into Politics (Changemakers Books, 2020).]
[Editor's Note: To read other articles in this special magazine issue, visit the beautifully designed e-reader version.]
Following the Footsteps of a 105-Year-Old Sprinter
No human has run a distance of 100 meters faster than Usain Bolt’s lightning streak in 2009. He set this record at age 22. But what will Bolt’s time be when he’s 105?
At the Louisiana Senior Games in November 2021, 105-year-old Julia Hawkins of Baton Rouge became the oldest woman to run 100 meters in an official competition, qualifying her for this year's National Senior Games. Perhaps not surprisingly, she was the only competitor in the race for people 105 and older. In this Leaps.org video, I interview Hawkins about her lifestyle habits over the decades. Then I ask Steven Austad, a pioneer in studying the mechanisms of aging, for his scientific insights into how those aspiring to become super-agers might follow in Hawkins' remarkable footsteps.
Following the Footsteps of a 105-Year-Old Sprinter
No human has run a distance of 100 meters faster than Usain Bolt’s lightning streak in 2009. He set this record at age 22. But what will Bolt’s time be when ...Matt Fuchs is the editor-in-chief of Leaps.org. He is also a contributing reporter to the Washington Post and has written for the New York Times, Time Magazine, WIRED and the Washington Post Magazine, among other outlets. Follow him on Twitter @fuchswriter.
Monkeypox produces more telltale signs than COVID-19. Scientists think that a “ring” vaccination strategy can be used when these signs appear to help with squelching the current outbreak of this disease.
A new virus has emerged and stoked fears of another pandemic: monkeypox. Since May 2022, it has been detected in 29 U.S. states, the District of Columbia, and Puerto Rico among international travelers and their close contacts. On a worldwide scale, as of June 30, there have been 5,323 cases in 52 countries.
The good news: An existing vaccine can go a long way toward preventing a catastrophic outbreak. Because monkeypox is a close relative of smallpox, the same vaccine can be used—and it is about 85 percent effective against the virus, according to the World Health Organization (WHO).
Also on the plus side, monkeypox is less contagious with milder illness than smallpox and, compared to COVID-19, produces more telltale signs. Scientists think that a “ring” vaccination strategy can be used when these signs appear to help with squelching this alarming outbreak.
How it’s transmitted
Monkeypox spreads between people primarily through direct contact with infectious sores, scabs, or bodily fluids. People also can catch it through respiratory secretions during prolonged, face-to-face contact, according to the Centers for Disease Control and Prevention (CDC).
As of June 30, there have been 396 documented monkeypox cases in the U.S., and the CDC has activated its Emergency Operations Center to mobilize additional personnel and resources. The U.S. Department of Health and Human Services is aiming to boost testing capacity and accessibility. No Americans have died from monkeypox during this outbreak but, during the COVID-19 pandemic (February 2020 to date), Africa has documented 12,141 cases and 363 deaths from monkeypox.
Ring vaccination proved effective in curbing the smallpox and Ebola outbreaks. As the monkeypox threat continues to loom, scientists view this as the best vaccine approach.
A person infected with monkeypox typically has symptoms—for instance, fever and chills—in a contagious state, so knowing when to avoid close contact with others makes it easier to curtail than COVID-19.
Advantages of ring vaccination
For this reason, it’s feasible to vaccinate a “ring” of people around the infected individual rather than inoculating large swaths of the population. Ring vaccination proved effective in curbing the smallpox and Ebola outbreaks. As the monkeypox threat continues to loom, scientists view this as the best vaccine approach.
With many infections, “it normally would make sense to everyone to vaccinate more widely,” says Wesley C. Van Voorhis, a professor and director of the Center for Emerging and Re-emerging Infectious Diseases at the University of Washington School of Medicine in Seattle. However, “in this case, ring vaccination may be sufficient to contain the outbreak and also minimize the rare, but potentially serious side effects of the smallpox/monkeypox vaccine.”
There are two licensed smallpox vaccines in the United States: ACAM2000 (live Vaccina virus) and JYNNEOS (live virus non-replicating). The ACAM 2000, Van Voorhis says, is the old smallpox vaccine that, in rare instances, could spread diffusely within the body and cause heart problems, as well as severe rash in people with eczema or serious infection in immunocompromised patients.
To prevent organ damage, the current recommendation would be to use the JYNNEOS vaccine, says Phyllis Kanki, a professor of health sciences in the division of immunology and infectious diseases at the Harvard T.H. Chan School of Public Health. However, according to a report on the CDC’s website, people with immunocompromising conditions could have a higher risk of getting a severe case of monkeypox, despite being vaccinated, and “might be less likely to mount an effective response after any vaccination, including after JYNNEOS.”
In the late 1960s, the ring vaccination strategy became part of the WHO’s mission to globally eradicate smallpox, with the last known natural case described in Somalia in 1977. Ring vaccination can also refer to how a clinical trial is designed, as was the case in 2015, when this approach was used for researching the benefits of an investigational Ebola vaccine in Guinea, Kanki says.
“Since Monkeypox spreads by close contact and we have an effective vaccine, vaccinating high-risk individuals and their contacts may be a good strategy to limit transmission,” she says, adding that privacy is an important ethical principle that comes into play, as people with monkeypox would need to disclose their close contacts so that they could benefit from ring vaccination.
Rapid identification of cases and contacts—along with their cooperation—is essential for ring vaccination to be effective. Although mass vaccination also may work, the risk of infection to most of the population remains low while supply of the JYNNEOS vaccine is limited, says Stanley Deresinski, a clinical professor of medicine in the Infectious Disease Clinic at Stanford University School of Medicine.
Other strategies for preventing transmission
Ideally, the vaccine should be administered within four days of an exposure, but it’s recommended for up to 14 days. The WHO also advocates more widespread vaccination campaigns in the population segment with the most cases so far: men who engage in sex with other men.
The virus appears to be spreading in sexual networks, which differs from what was seen in previously reported outbreaks of monkeypox (outside of Africa), where risk was associated with travel to central or west Africa or various types of contact with individuals or animals from those locales. There is no evidence of transmission by food, but contaminated articles in the environment such as bedding are potential sources of the virus, Deresinski says.
Severe cases of monkeypox can occur, but “transmission of the virus requires close contact,” he says. “There is no evidence of aerosol transmission, as occurs with SARS-CoV-2, although it must be remembered that the smallpox virus, a close relative of monkeypox, was transmitted by aerosol.”
Deresinski points to the fact that in 2003, monkeypox was introduced into the U.S. through imports from Ghana of infected small mammals, such as Gambian giant rats, as pets. They infected prairie dogs, which also were sold as pets and, ultimately, this resulted in 37 confirmed transmissions to humans and 10 probable cases. A CDC investigation identified no cases of human-to-human transmission. Then, in 2021, a traveler flew from Nigeria to Dallas through Atlanta, developing skin lesions several days after arrival. Another CDC investigation yielded 223 contacts, although 85 percent were deemed to be at only minimal risk and the remainder at intermediate risk. No new cases were identified.
How much should we be worried
But how serious of a threat is monkeypox this time around? “Right now, the risk to the general public is very low,” says Scott Roberts, an assistant professor and associate medical director of infection prevention at Yale School of Medicine. “Monkeypox is spread through direct contact with infected skin lesions or through close contact for a prolonged period of time with an infected person. It is much less transmissible than COVID-19.”
The monkeypox incubation period—the time from infection until the onset of symptoms—is typically seven to 14 days but can range from five to 21 days, compared with only three days for the Omicron variant of COVID-19. With such a long incubation, there is a larger window to conduct contact tracing and vaccinate people before symptoms appear, which can prevent infection or lessen the severity.
But symptoms may present atypically or recognition may be delayed. “Ring vaccination works best with 100 percent adherence, and in the absence of a mandate, this is not achievable,” Roberts says.
At the outset of infection, symptoms include fever, chills, and fatigue. Several days later, a rash becomes noticeable, usually beginning on the face and spreading to other parts of the body, he says. The rash starts as flat lesions that raise and develop fluid, similar to manifestations of chickenpox. Once the rash scabs and falls off, a person is no longer contagious.
“It's an uncomfortable infection,” says Van Voorhis, the University of Washington School of Medicine professor. There may be swollen lymph nodes. Sores and rash are often limited to the genitals and areas around the mouth or rectum, suggesting intimate contact as the source of spread.
Symptoms of monkeypox usually last from two to four weeks. The WHO estimated that fatalities range from 3 to 6 percent. Although it’s believed to infect various animal species, including rodents and monkeys in west and central Africa, “the animal reservoir for the virus is unknown,” says Kanki, the Harvard T.H. Chan School of Public Health professor.
Too often, viruses originate in parts of the world that are too poor to grapple with them and may lack the resources to invest in vaccines and treatments. “This disease is endemic in central and west Africa, and it has basically been ignored until it jumped to the north and infected Europeans, Americans, and Canadians,” Van Voorhis says. “We have to do a better job in health care and prevention all over the world. This is the kind of thing that comes back to bite us.”