Why Your Brain Falls for Misinformation – And How to Avoid It
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.]
A new type of cancer therapy is shrinking deadly brain tumors with just one treatment
Few cancers are deadlier than glioblastomas—aggressive and lethal tumors that originate in the brain or spinal cord. Five years after diagnosis, less than five percent of glioblastoma patients are still alive—and more often, glioblastoma patients live just 14 months on average after receiving a diagnosis.
But an ongoing clinical trial at Mass General Cancer Center is giving new hope to glioblastoma patients and their families. The trial, called INCIPIENT, is meant to evaluate the effects of a special type of immune cell, called CAR-T cells, on patients with recurrent glioblastoma.
How CAR-T cell therapy works
CAR-T cell therapy is a type of cancer treatment called immunotherapy, where doctors modify a patient’s own immune system specifically to find and destroy cancer cells. In CAR-T cell therapy, doctors extract the patient’s T-cells, which are immune system cells that help fight off disease—particularly cancer. These T-cells are harvested from the patient and then genetically modified in a lab to produce proteins on their surface called chimeric antigen receptors (thus becoming CAR-T cells), which makes them able to bind to a specific protein on the patient’s cancer cells. Once modified, these CAR-T cells are grown in the lab for several weeks so that they can multiply into an army of millions. When enough cells have been grown, these super-charged T-cells are infused back into the patient where they can then seek out cancer cells, bind to them, and destroy them. CAR-T cell therapies have been approved by the US Food and Drug Administration (FDA) to treat certain types of lymphomas and leukemias, as well as multiple myeloma, but haven’t been approved to treat glioblastomas—yet.
CAR-T cell therapies don’t always work against solid tumors, such as glioblastomas. Because solid tumors contain different kinds of cancer cells, some cells can evade the immune system’s detection even after CAR-T cell therapy, according to a press release from Massachusetts General Hospital. For the INCIPIENT trial, researchers modified the CAR-T cells even further in hopes of making them more effective against solid tumors. These second-generation CAR-T cells (called CARv3-TEAM-E T cells) contain special antibodies that attack EFGR, a protein expressed in the majority of glioblastoma tumors. Unlike other CAR-T cell therapies, these particular CAR-T cells were designed to be directly injected into the patient’s brain.
The INCIPIENT trial results
The INCIPIENT trial involved three patients who were enrolled in the study between March and July 2023. All three patients—a 72-year-old man, a 74-year-old man, and a 57-year-old woman—were treated with chemo and radiation and enrolled in the trial with CAR-T cells after their glioblastoma tumors came back.
The results, which were published earlier this year in the New England Journal of Medicine (NEJM), were called “rapid” and “dramatic” by doctors involved in the trial. After just a single infusion of the CAR-T cells, each patient experienced a significant reduction in their tumor sizes. Just two days after receiving the infusion, the glioblastoma tumor of the 72-year-old man decreased by nearly twenty percent. Just two months later the tumor had shrunk by an astonishing 60 percent, and the change was maintained for more than six months. The most dramatic result was in the 57-year-old female patient, whose tumor shrank nearly completely after just one infusion of the CAR-T cells.
The results of the INCIPIENT trial were unexpected and astonishing—but unfortunately, they were also temporary. For all three patients, the tumors eventually began to grow back regardless of the CAR-T cell infusions. According to the press release from MGH, the medical team is now considering treating each patient with multiple infusions or prefacing each treatment with chemotherapy to prolong the response.
While there is still “more to do,” says co-author of the study neuro-oncologist Dr. Elizabeth Gerstner, the results are still promising. If nothing else, these second-generation CAR-T cell infusions may someday be able to give patients more time than traditional treatments would allow.
“These results are exciting but they are also just the beginning,” says Dr. Marcela Maus, a doctor and professor of medicine at Mass General who was involved in the clinical trial. “They tell us that we are on the right track in pursuing a therapy that has the potential to change the outlook for this intractable disease.”
Since the early 2000s, AI systems have eliminated more than 1.7 million jobs, and that number will only increase as AI improves. Some research estimates that by 2025, AI will eliminate more than 85 million jobs.
But for all the talk about job security, AI is also proving to be a powerful tool in healthcare—specifically, cancer detection. One recently published study has shown that, remarkably, artificial intelligence was able to detect 20 percent more cancers in imaging scans than radiologists alone.
Published in The Lancet Oncology, the study analyzed the scans of 80,000 Swedish women with a moderate hereditary risk of breast cancer who had undergone a mammogram between April 2021 and July 2022. Half of these scans were read by AI and then a radiologist to double-check the findings. The second group of scans was read by two researchers without the help of AI. (Currently, the standard of care across Europe is to have two radiologists analyze a scan before diagnosing a patient with breast cancer.)
The study showed that the AI group detected cancer in 6 out of every 1,000 scans, while the radiologists detected cancer in 5 per 1,000 scans. In other words, AI found 20 percent more cancers than the highly-trained radiologists.
Scientists have been using MRI images (like the ones pictured here) to train artificial intelligence to detect cancers earlier and with more accuracy. Here, MIT's AI system, MIRAI, looks for patterns in a patient's mammograms to detect breast cancer earlier than ever before. news.mit.edu
But even though the AI was better able to pinpoint cancer on an image, it doesn’t mean radiologists will soon be out of a job. Dr. Laura Heacock, a breast radiologist at NYU, said in an interview with CNN that radiologists do much more than simply screening mammograms, and that even well-trained technology can make errors. “These tools work best when paired with highly-trained radiologists who make the final call on your mammogram. Think of it as a tool like a stethoscope for a cardiologist.”
AI is still an emerging technology, but more and more doctors are using them to detect different cancers. For example, researchers at MIT have developed a program called MIRAI, which looks at patterns in patient mammograms across a series of scans and uses an algorithm to model a patient's risk of developing breast cancer over time. The program was "trained" with more than 200,000 breast imaging scans from Massachusetts General Hospital and has been tested on over 100,000 women in different hospitals across the world. According to MIT, MIRAI "has been shown to be more accurate in predicting the risk for developing breast cancer in the short term (over a 3-year period) compared to traditional tools." It has also been able to detect breast cancer up to five years before a patient receives a diagnosis.
The challenges for cancer-detecting AI tools now is not just accuracy. AI tools are also being challenged to perform consistently well across different ages, races, and breast density profiles, particularly given the increased risks that different women face. For example, Black women are 42 percent more likely than white women to die from breast cancer, despite having nearly the same rates of breast cancer as white women. Recently, an FDA-approved AI device for screening breast cancer has come under fire for wrongly detecting cancer in Black patients significantly more often than white patients.
As AI technology improves, radiologists will be able to accurately scan a more diverse set of patients at a larger volume than ever before, potentially saving more lives than ever.