Science Denial and COVID Conspiracy Theories: Potential Neurological Mechanisms and Possible Responses | Dementia and Cognitive Impairment | JAMA | JAMA Network
[Skip to Navigation]
Sign In
November 2, 2020

Science Denial and COVID Conspiracy Theories: Potential Neurological Mechanisms and Possible Responses

Author Affiliations
  • 1Memory and Aging Center, Department of Neurology, Weill Institute for Neurosciences, University of California, San Francisco
JAMA. 2020;324(22):2255-2256. doi:10.1001/jama.2020.21332

The US public health response to coronavirus disease 2019 (COVID-19) has been dismal, characterized by antimask behavior, antivaccine beliefs, conspiracy theories about the origins of COVID-19, and vocal support by elected officials for unproven therapies. Less than half of the people in the US heed health recommendations to wear a mask when out in public.1 Antiscience rhetoric has consequences. While only 4% of the world’s population resides in the US, the US has accounted for 20% of the world’s deaths related to COVID-19 and has performed less well than several other wealthy nations.2 Low science literacy contributes to denial of science. The relationship between antiscience viewpoints and low science literacy underscores new findings regarding the brain mechanisms that form and maintain false beliefs.

Science Literacy Is Essential

COVID-19 science is complex, and the public is presented with a dizzying array of graphs, statistics, and proposed therapies. Also, communications by scientists changed as they learned about the infectivity and virulence of COVID-19, exacerbating mistrust of scientists by some. In 2015, in a survey of 11 000 12th-grade students who took the National Assessment of Educational Progress (NAEP) science assessment, only 22% were proficient or better in science, and 40% were rated as having “below basic knowledge.”3 Education matters. In a study that included 9654 US adults, 48% of those who had a high school education or less believed there was some truth to the conspiracy theory that COVID-19 was planned but only 15% among those with some postgraduate training endorsed this idea.4

How does low science literacy cause otherwise rational and competent people to misunderstand the threat of COVID-19 and allow them to feel more comfortable with false data than with scientifically sound information? Beliefs grounded in false information, just like those grounded in truth, have neural origins and reflect connections in dedicated brain circuits. Individuals are organized to hold beliefs and to evaluate their merit based on facts and experiences. Studies of neurodegenerative disorders that target selective brain networks shed light on the neural mechanisms that underlie the creation and sustenance of beliefs that are not based in reality.

Neurological Mechanisms for False Beliefs

People hold beliefs with varying levels of truth. False beliefs are common in neurodegenerative disorders, particularly dementia with Lewy bodies and frontotemporal dementia. In neurodegenerative and psychiatric disorders, false beliefs range from accusations of theft, delusions of grandeur, to misidentification of people. Recent theories suggest that false beliefs emerge when there are neuropsychological impairments that (1) promote formation of false beliefs due to faulty sensory information and (2) hinder rejection of a belief due to faulty prefrontal systems that evaluate thoughts and beliefs.5 The content of false beliefs in dementia with Lewy bodies and frontotemporal dementia differ but may offer insights into the shared neural mechanisms by which humans misperceive information. With both, the brain receives distorted sensory information that interferes with accurate interpretation of the world and lacks the circuitry needed to determine whether information received is true or false.

A recognized manifestation of dementia with Lewy bodies is Capgras syndrome, the false belief that a loved one has been replaced by an impostor. Capgras is associated with dysfunction in the retrosplenial cortex, a brain region involved with encoding familiarity, and the right frontal cortex, a region involved with belief evaluation.6 Also, there is dysfunction in the fusiform gyrus, which feeds information about an individual’s face into memory systems in the temporal lobe and familiarity systems in retrosplenial cortex, allowing comparison of each face with previously encountered faces. What seems like a bizarre delusion is a situation in which faulty information about a face and its familiarity leads to an internally consistent, but false, conclusion. Contributing to the false belief, many people with dementia with Lewy bodies have dysfunction in the frontal brain circuitry required to determine the plausibility of a conclusion.

In frontotemporal dementia, visual processing is intact, making Capgras rare, but other false beliefs occur. Sometimes, these patients believe they have won the lottery, leading them to spend money they do not have. With dementia with Lewy bodies, misbelief begins with a faulty perception of a face. With frontotemporal dementia, it begins with a gratifying idea about wealth. Evaluating the plausibility of a person’s ideas requires functional prefrontal circuits. When people reflect on their thoughts, circuits in the frontal lobes are needed to confirm or refute whether the ideas are valid. When pondering wealth, circuits in the frontal lobes search the brain to verify or deny a desire to be rich with factual data. If frontal systems responsible for monitoring the credibility of ideas are dysfunctional, false conclusions are made about the veracity of an idea.

False Beliefs About COVID-19

How do these distinct mechanisms—distorted sensory information or faulty monitoring of ideas—have relevance to cognitively normal and healthy people without dementia who develop false beliefs? For someone without strong science literacy, absorbing and interpreting a graph of data about COVID-19 infections may be as difficult as it is for someone with dementia with Lewy bodies to interpret a face. Without reliable sensory data, individuals may be forced to look for other sources of information that resonate with their own feelings, including conspiracies that deny the existence of a threat. Rather than engaging with information that is difficult to “see” and that may require changes in behavior, it may be easier to take in data that are simple and reassuring. Conspiracy theories may bring security and calm, as with the patient with frontotemporal dementia who is content to believe they are rich. This problem is magnified by social media because before the internet, conspiracy theories usually remained siloed and quickly died off due to lack of supporters. Now, social media–fueled echo chambers amplify these theories, reinforcing false beliefs and discouraging people from seeking the truth.

False beliefs about COVID-19 are also more likely to occur in someone who has faulty systems for monitoring and evaluating scientific information. When physicians determine the efficacy of medication like hydroxychloroquine, they read research studies, evaluate the adverse effects of the drug, and some may even study the pharmacokinetics before deciding whether prescribing the medicine is worth the risk. This process of logic and reasoning is not accessible just to physicians or scientists. It is learned in elementary school and high school and is later sharpened by solving problems in work, college, and graduate school. If that process of balancing and comparing all sides of an issue is not taught, an individual is more susceptible to believing false information. Developing frontal circuitry to support the process of reasoning is part of education and science literacy and stands at the core of a healthy democracy.

Possible Responses

The COVID-19 epidemic reinforces the challenges of science denial. The medical community should mount systematic efforts around science education beginning in childhood and across the lifetime. Scientists, clinicians, and public health experts should engage in dialogue on issues of public health such as masks, vaccines, and medications. Accessible presentations should be part of every medical office and health care system. Attractive and accessible websites that post reliable data on health should counteract the false narratives that harm the health of the US (and other countries). A systematic analysis of “what went wrong” with COVID-19 policies during and after this pandemic is the responsibility of the scientific community. In addition, working with politicians to establish national policies to support rational science is critical. The practice of medicine is at the front line of the national concerns and conflicts surrounding truth and health. When science wins, everyone wins.

Back to top
Article Information

Corresponding Author: Bruce L. Miller, MD, Memory and Aging Center, University of California, San Francisco (UCSF), 675 Nelson Rising Ln, Ste 190, PO Box 1207, San Francisco, CA 94143 (

Published Online: November 2, 2020. doi:10.1001/jama.2020.21332

Conflict of Interest Disclosures: Dr Miller reports serving on the advisory committee of the Cambridge National Institute for Health Research (NIHR) Biomedical Research Centre; serving on the board of directors of the John Douglas French Alzheimer's Foundation and Safely You; serving as a medical advisor for the Bluefield Project; serving as a consultant for the Rainwater Charitable Foundation, Stanford Alzheimer's Disease Research Center, the scientific advisory board of the Buck Institute, the Larry L. Hillblom Foundation, University of Texas Center for Brain Health, the external advisory board of the University of Washington Alzheimer's Disease Research Center, and external advisory board of the Harvard University Alzheimer's Disease Research Center; receiving royalties from Guilford Press, Cambridge University Press, Johns Hopkins Press, and Oxford University Press; being an editor of Neurocase, and section editor of Frontiers in Neurology; and receiving grant support from the Bluefield Project to Cure Frontotemporal Dementia Research.

Funding/Support: This work is supported by grant P01 AG019724 from the National Institute on Aging.

Role of the Funder/Sponsor: The sponsor had no role in preparation, review, approval, or decision to submit the manuscript for publication.

Additional Contributions: I thank Virginia Sturm, PhD, John Douglas French Foundation Professor; Serggio Lanata, MD, MS, Roland Nyegaard Endowed Professorship, and Gloria Aguirre, BA; University of California, San Francisco, Niall Kavanagh, MS, Global Brain Health Institute; and Caroline Prioleau, BA, University of California, San Francisco, for editorial assistance with the manuscript, none of whom received compensation for their contributions.

Cornwall  W.  Just 50% of Americans plan to get a COVID-19 vaccine: here’s how to win over the rest.   Science. Posted June 30, 2020. doi:10.1126/science.abd6018 Google Scholar
Bilinski  A, Emanuel  EJ.  COVID-19 and excess all-cause mortality in the US and 18 comparison countries.   JAMA. Published online October 12, 2020. doi:10.1001/jama.2020.20717PubMedGoogle Scholar
The Nation’s Report Card. 2015 Student questionnaire results: classroom instruction for mathematics, reading, and science. Accessed September 8, 2020.
Schaeffer  K. A look at the Americans who believe there is some truth to the conspiracy theory that COVID-19 was planned. Pew Research Center; July 24, 2020. Accessed September 8, 2020.
Coltheart  M.  The neuropsychology of delusions.   Ann N Y Acad Sci. 2010;1191:16-26. doi:10.1111/j.1749-6632.2010.05496.x PubMedGoogle ScholarCrossref
Darby  RR, Laganiere  S, Pascual-Leone  A, Prasad  S, Fox  MD.  Finding the imposter: brain connectivity of lesions causing delusional misidentifications.   Brain. 2017;140(2):497-507. doi:10.1093/brain/aww288 PubMedGoogle ScholarCrossref
Limit 200 characters
Limit 25 characters
Conflicts of Interest Disclosure

Identify all potential conflicts of interest that might be relevant to your comment.

Conflicts of interest comprise financial interests, activities, and relationships within the past 3 years including but not limited to employment, affiliation, grants or funding, consultancies, honoraria or payment, speaker's bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued.

Err on the side of full disclosure.

If you have no conflicts of interest, check "No potential conflicts of interest" in the box below. The information will be posted with your response.

Not all submitted comments are published. Please see our commenting policy for details.

Limit 140 characters
Limit 3600 characters or approximately 600 words
    12 Comments for this article
    Science as an Absolute Guide Going Forward
    Charles S. Mills, MD | Elliot Health System
    I applaud Dr Miller's article and would subscribe to many of its conclusions. But I do see a frailty in his final statement "When science wins, everyone wins". One of the problems is that scientific fact is not immutable and does constantly evolve. As Lorraine Daston states in her 2005 article, " Scientific Error and the Ethos of Belief":

    For the modern sciences, the boundary between what counts as established and reliable knowledge what is viewed as hypothesis and conjecture and tentative belief shifts constantly, according to the dynamic of research and debate. Today's reigning theory may be toppled by tomorrow's finding; within the span of a single scientific career the received wisdom of a discipline may be fundamentally revised not once but several times, What was once judged to be audacious speculation may be confirmed by ingenious empirical tests: conversely the very axioms... may be confronted with alternatives. On the basis of the latest research, knowledge is demoted to the status of mere belief and belief promoted to that of knowledge; hence the instability of the boundary between them and the dynamism of the modern sciences." (1)

    COVID information and practice, in part due to the novelty of the infection, and the absence of a timeline of experience to test premises of practice demonstrates this difficulty for scientific dictum to 'win'. An analysis of the statements propagated for public consumption over the 9 months of this pandemic in the US demonstrates that difficulty. Part of this is fed by the need for the news cycle to be filled with politically charged descriptions that then further cloud the science of understanding. Other than basic or universal epidemiologic truths (masks work, social distancing works, open spaces are safer than closed spaces) the nuanced secondary statements are harder to face as concrete science. And of course the power of political agenda further complicates all of this scientific explanation.

    I would emphasize rather that in the face of a novel illness, we should not hang our beliefs on 'Breaking News' analysis but rather simply on the truth of Dr Easton's statement/explanation and on core truths. The issue of belief systems may not be that they mirror various forms of dementing process but rather that the processes described remain opaque in many of their scientific parameters.


    1. Daston, Lorraine. “Scientific Error and the Ethos of Belief.” Social Research, vol. 72, no. 1, 2005, pp. 1–28. JSTOR, Accessed 3 Nov. 2020.
    Science Denial and COVID Conspiracy Theories
    Khondakar Hasanat, MD | Practice
    Almost all of populations who decry mask use, safety of established vaccinations, and maintaining of safe distance, or who question the magnitude of the seriousness of Covid are otherwise neuro-physiologically and neuro-anatomically normal. Brain activation on fMRI or psychological tests like MMPI or Rorschach possibly will only elicit vague overlapping or insignificant findings .

    Culture might have more relevance to explain the phenomenon. It is always evolving. When someone in Brazil or India or the US thinks Covid is not a problem or HCQ works or masks are not required they might be connecting different
    loci which originate from different financial, religious, and local partisan politics in addition to the confusing information from leaders. 

    In America, this particular segment would change their minds if tomorrow president decides to do so . This somersault is related to political culture of “Us vs Them”
    What's Our Response Strategy?
    John Griffith, MBA | Prof. Emeritus, Univ. of Michigan School of Public Health
    Dr. Miller’s careful tracing takes denial to micro levels. That’s certainly useful. As a non-expert, I’d like more information on the link between education and neurofunctioning—what should we do to reduce our kids' chance of difficulty? And even—is there anything we can do with existing adult and adolescent populations?
    The macro end of the denial problem is in fact a major threat to medicine, medical care, and public health. Our professional organizations—public health, hospitals, clinics, even drugstores—have an inescapable empirical foundation. All patient care and prevention actions and conversations assume empiricism. The Trump administration has systematically and repeatedly assaulted
    that assumption. What’s worse, many millions have believed them. What next? How do we recover?
    Meaning Outranks Neurology
    John Jacobs, MD | Private Practice
    Attributing anti-science views to neuropathology sounds more like belief than science.. And mention the fusiform gyrus and Lewy bodies, and you'll turn off all the anti-vaxers. They'd know you're trying to pull rank on them by knowing more science. And they'd also know they're pulling rank on you, because their non-science outranks your science, because it has more meaning to them. It could be Christian, astrological, political, whatever. People wish for an ideal meaningful something or another.

    Science is discarded precisely because it is based not on belief, but on falsifiable
    hypotheses. In contrast, no one is going to convince me I'm wrong when I believe in Mom, apple pie, and the American flag.

    Dr Miller writes, "Individuals are organized to hold beliefs and to evaluate their merit based on facts and experiences." In fact, organized individuals are irrational and follow a herd instinct. Neuropathological explanations of belief sound simple and reassuring, but do not take into account humans' wish for ideals, except to the extent they are themselves more mythology than science. Historical literacy rather than science literacy might help. The history of propaganda might be the place to start.
    Disturbing Analogy
    Giovanna Calabrese, Medical Doctor, PhD Psych | Casa di Cura Igea, Milan, Italy
    I might agree with the need to improve science literacy. However I find quite disturbing the parallelism between "false beliefs" and neurodegenerative disorders ("People hold beliefs with varying levels of truth. False beliefs are common in neurodegenerative disorders, particularly dementia with Lewy bodies and frontotemporal dementia."). It is not long ago that political opponents ended up in psychiatric hospitals.
    Differences of Opinion May Not be Pathological
    David Bell, MBBS, MTH, PhD | Public health consultant
    This article is disturbing. Attributing pathological or physiological differences to thought processes that lead to opinions considered 'inferior' from a scientific point of view perhaps belongs better in other times.

    Particularly so as the article is premised on 'false beliefs about COVID'. The mask issue, for example, is complex: ignoring this is perhaps more like denialism than acknowledging it. To state that someone skeptical of community mask impact has specific pathology is essentially saying that the authors of previous CDC and WHO guidelines on respiratory epidemic management suffered from such pathology. It also implies that the authors meta-analyses of
    RCTs were similarly afflicted or that the studies were massively flawed. This seems unrealistic.

    The severity of COVID is not frequently ‘denied’ but is relative, like all diseases. It is a potentially fatal condition affecting all ages but heavily concentrated in elderly people with multiple co-morbidities, while in children the IFR is lower than that for influenza. The average age of death is at or above the average all-cause age in most western countries, and many of these countries will have all-cause mortality this year not unlike recent years despite COVID outbreaks. This is fact, not denialism, as is the undoubted impact on younger people of reduced medical care and income loss through COVID responses. The preferred approach to these issues should be to assess costs and benefits of interventions in context, and based on hard evidence, not to suggest that those that disagree with an interpretation of data, or that apportion different weights to outcomes (e.g. keeping an elderly person alive vs. risking a child's psychological health or reducing availability of cancer screening), are suffering from an organic, pathological malady.

    The latter risks taking the medical profession down a dangerous path that will not benefit society.
    Dealing with COVID-19 Science Denial and Conspiracy Theories
    Michael McAleer, PhD (Econometrics),Queen's | Asia University, Taiwan
    Repeating consistent and easy to understand (simple, not simplistic) scientific statements in the media, social media, and scientific social media is essential in working to convince members of society about the most efficient methods for dealing with the COVID-pandemic.

    As explained carefully and informatively in the viewpoint, conspiracy theories are widespread, but trying to deny their legitimacy will see science descending to the same abysmally  low level.

    Science deniers and advocates of fake news are not likely ever to be convinced, but the only workable response is to repeat consistent and interpretable recommendations in a calm manner, including the wearing
    of masks and widely accepted social measures.

    This is what scientists do in their professional lives, but the need to act more frequently and convincingly has never been more urgent for the international community.
    Science Denial In The Most Literate Country
    Shehzad Khan, MD | Private Practice
    Despite being the most literate nation the US has suffered the most due to COVID. That means there is more to it than mere low science literacy. Otherwise the poor and illiterate countries would have been worse sufferers.

    More than lack of enough science literacy, it was the official endorsement of pseudoscience with utter disregard for true science that led to the mess. A top infection expert was being ridiculed and threatened for being scientific while the government looked the other way. Such acts sent wrong signals among the community who started believing that COVID is a non-issue and
    an overblown thing.
    Science Illiteracy Among Physicians
    Amarlal Dave, MD | General Pediatrician
    Rand Paul, Scott Atlas, Stella Immanuel, and many of the colleagues I have interacted recently are the manifestation of this trend and are among the pall bearers of science. One of my colleagues in a county society meeting boldly declared that the real rate of Covid deaths among the people 60 years and above was 1 in 19 million!, a pure fabrication of data he claimed to have gotten from some source at Stanford University! I heard no dissenting voice among the few participants there. As mentioned in the article the same colleague produced some impressive graphs and diagrams from various social media sources to instill authenticity.

    The point is that belief in misinformation is pervasive even among so-called "scientists" ! It would be provocative to get some numbers on this matter, because when the source is from a scientist or a physician it has built-in authenticity for the lay public. Inaccurate information peddled as authentic is far more dangerous to the society.

    In any given scientific community we have to be aware not only of the existence of such dynamic affecting the integrity of science, but to counter them effectively. Not too much is known about how to achieve that goal and an inquiry into this matter is urgently needed.
    Overlooked Response
    Kristina Dorsett, MS Information Sciences | Heath Science Liaison, Research & Instruction Librarian, Widener University
    This article contains many wonderful responses to the proposed problem of science literacy, but left out a huge resource - librarians! We are educated and skilled at translating information. We have an impact on society beginning at a young age. The days of librarians being "keepers of the books" are over. We are designers and creators, we develop physical and digital spaces to stimulate collaboration and learning. The suggestion of websites is one that information scientists have been working on for years - and we have been shouting "USE US! WE'RE HERE TO HELP!"

    Libraries are well-connected
    and looking for events and promotions that will help their users. Please include us in the front lines of the fight against science denial.
    Quite a Doubtful Hypothesis
    Andrea Bellelli, MD | Sapienza University of Rome, Italy
    I am extremely skeptical about the attempt to infer a diagnosis from a belief. It reminds me of Soviet political psychiatry. Dementia is caused by loss of neurons, and is a cause of impaired reasoning; but trying to establish a parallel between a wrong idea and a disease is hazardous. Wrong ideas are widespread and everyone may at some point believe in one, simply because being wrong is common. Moreover Covid-19 deniers are a poorly defined group, and attributing to its members one and the same error in reasoning is not justified. The group may even include persons who have reasonable doubts on the measures adopted to control the pandemic.
    Well Written and Thoughtful
    Osman Ahmed, MD Dr.PH | Consultant, Public Health, Analytics
    This article is the opinion of the author. While it is supported by theoretical evidence and valid hypothesis, it obviously has no conclusive findings as cause and effect for an observed behavior except perhaps in dementia. It invites us, scientists and physicians, to understand possible mechanisms that are in play for some deniers of vaccine efficacy and of COVID 19 presence or origins. While we can argue the merits of analogy or comparison, we should be able to understand how to begin a conversation with deniers or believers in conspiracy theories. COVID has shown us that there are a lot to learn about factors that may be involved in human behavior. The more we know will lead us to have more useful conversations, tools for motivational interviewing, and perhaps conveying a science-based simple way to explain complex issues to our patients. These issues and conversations have been made more difficult in the age of a half-backed, fast moving Information Age fueled by social media.