Two ways to be wrong: The psychology of conspiracy beliefs

Two ways to be wrong

The psychology of conspiracy beliefs
Timur Sevincer and Nikil Mukerji in conversation with Jan-Willem van ProoijenGWUP-Artikel in der Google-Suche bevorzugt anzeigen lassen.★ Jetzt aktivieren ausblenden

Interview auf Deutsch lesen

Jan-Willem van Prooijen studies why people believe that powerful groups act in secret. In conversation with Timur Sevincer and Nikil Mukerji he explains where legitimate suspicion ends, which of his own field’s convictions have not survived closer inspection, and why the error his discipline does not study may be the more interesting one.

Ein Auge blickt durch ein dunkles Rohr hindurch.

Photo by Mario Heller on Unsplash

Not the most conspiratorial time in history

Sevincer: As skeptics, we care about pseudoscience, but also about exaggerated, distorted, or plainly false scientific claims. Which claims about your area of research – the psychology of conspiracy theories – are most often misrepresented?

van Prooijen: Two things. The first is the idea that conspiracy belief in the population is now more widespread than ever. I think that is really a mistake. What is more accurate is that the online environment surely has an impact and has probably caused a resurgence. But throughout history, I don’t think this is the most conspiratorial time ever. In the 1930s, in Germany but everywhere in Europe, there were tons of conspiracy theories — Jewish conspiracies for world domination. In medieval times conspiracy theories were also very widespread: that young women were witches who conspired with the devil, that Jews poisoned the water supply and thus caused the bubonic plague. They are really of all times.

And today, people generally know much more about how the world works. As academics, we focus on those who believe conspiracy theories, but the majority of the population is not particularly conspiratorial. On average, people have become more rational over time.

Recent work comparing surveys across recent decades found no increase over time (1). I believe that, although I struggle to reconcile that with some developments we might associate with conspiracy belief: declining vaccination, support for populist movements, and increasing polarization.

Sevincer: And the second misconception?

van Prooijen: This one is among researchers, not the public, and it is something I have been working on lately. There is a widespread notion in the field about the belief in contradictory conspiracy theories: the idea that people tend to believe two mutually exclusive theories at the same time, such as that Princess Diana was murdered —

Mukerji: — and that she faked her own death.

van Prooijen: Exactly. That rests on two claims: that such beliefs are positively correlated, and that holding them simultaneously is widespread.

In 2023 I published a paper showing that the correlation is a statistical artifact (2). It is caused almost entirely by the many people in the sample who disbelieve both theories. If you think it was simply a car accident, you disbelieve that she was murdered and you disbelieve that she faked her death — and that also produces a positive correlation. A recent study by Miani et al. (2026) reaches a somewhat different conclusion about how common contradictory conspiracy theories actually are (3). However, I have a new paper under review showing that the numbers are wildly exaggerated as well. It does occur, but it is extremely rare.

Nobody wants to be called a conspiracy theorist

Sevincer: Then let me turn to what I find the harder problem — how to tell a legitimate suspicion from an irrational one. Some conspiracies are real: Watergate turned out to be true, and the label “conspiracy theorist” can itself be used to discredit ideas. I have found the line genuinely hard to draw in some cases. In the 1990s, after the Kevin Costner film about the Kennedy assassination, I thought there might be more behind it than a single shooter — today the evidence convinces me there wasn’t. And when COVID began, my first reaction was that the lab-leak idea sounded like just another conspiracy theory. But I went back and forth and came to think that, at least at that stage, it was a hypothesis that should not simply be dismissed.

Mukerji: A cover-up would have been the conspiracy, strictly speaking.

Sevincer: A cover-up, yes. Any advice on how to handle this conundrum?

van Prooijen: There can be very legitimate suspicions or accusations of corruption, yes. And there is a first lesson in the label itself: the term conspiracy theory has become pejorative. Karen Douglas, Robbie Sutton, and I have investigated how people use it, and we mostly reserve it for ideas we do not believe ourselves (4). I don’t think that, as a scientist, you should use it that way, because then the term becomes empty.

Take COVID. There has since been a publication in Science (5) and even more recently, the weight of available evidence has been judged to favor a zoonotic origin associated with the Huanan market (6). Before that, it was what you say — a hypothesis. As long as there is no clear evidence either way, I don’t think the label helps. It is a label you should be very careful with, because it can also be a way to smother valid criticism or valid dissent of opinion.

Mukerji: I have been on the receiving end of that. When Adriano Mannino and I were warning about COVID early in the pandemic (7), some of the people taking the danger seriously were right-wing extremists. So I found myself explaining to journalists that I wasn’t spreading a conspiracy theory but passing on data from researchers in Asia. Then things flipped: the right-wing extremists said the lockdown was the conspiracy, and we were mainstream again. It showed me how damaging the label itself can be.

van Prooijen: There is even a meta-conspiracy theory about exactly that: some conspiracy theorists think the CIA invented the term to suppress legitimate criticism.

Mukerji: Historically that is among the first occurrences of the term, isn’t it?

van Prooijen: No. I know what you are referring to — the report after the Kennedy assassination. The term occurs there only once or twice, really just as a factual description of the conspiracy theories circulating after the murder, such as that Oswald did not act alone. And it was already in use before that — Popper, for example, used it in the 1940s. So no, the CIA did not invent the term.

A theory about a possible conspiracy

Sevincer: Maybe it helps to say what a conspiracy theory actually is, and how it is defined.

van Prooijen: The simple definition is the belief that multiple actors are colluding in secret agreements to pursue goals widely seen as malevolent, immoral or criminal. That entails a couple of things. There are always multiple people. It takes place in secret — if it is out in the open, people are just being corrupt. And it has to involve malevolent intentions. If you conspire to surprise a colleague with a party, that is not what we study.

Mukerji: Is that a scientific concept, or a folk concept based on what people associate with the term?

van Prooijen: I would say it is both, and the two do not always align. The folk concept is these bizarre, extreme conspiracy theories that are clearly false. The scientific concept can also include quite plausible ideas that simply have not been proven yet. That is the key difference.

Mukerji: But if a conspiracy theory ceases to be a theory once it is confirmed, there is a problem. We still call evolution a theory even though the evidence for it is overwhelming. And if you define conspiracy theories as unconfirmed, you risk making belief in them sound irrational by definition.

van Prooijen: Something can be unconfirmed and there can still be very strong indications in a certain direction. If there are good reasons to suspect a conspiracy, then it does not have to be irrational to investigate it.

Mukerji: But then when is it confirmed enough to become a fact?

van Prooijen: That takes us into very philosophical territory. At what point is something established enough, proven enough, that you can say: this is no longer a theory, this is a fact? I am not equipped to answer that in a few sentences.

There is another word for a conspiracy that is real

Sevincer: So where does the line actually run?

van Prooijen: Keep in mind that there is a different word for an actual conspiracy, and that is corruption. Corruption is a major problem in many countries. There is a grey area between legitimate suspicions of corruption and irrational conspiracy theorizing, and it is not always clear where to draw the line.

As a scientist, I think you should use the term conspiracy theory simply for suspicions of conspiracies that are not proven yet. And that does not have to be pejorative. In 1972 Woodward and Bernstein started investigating the Watergate scandal. By every scientific definition, they were pursuing a conspiracy theory at that time — except that it turned out true. The evidence eventually supported their theory. Watergate, the Volkswagen diesel scandal, Milli Vanilli: these were real conspiracies.

Sevincer: Then what distinguishes the investigator from the conspiracy theorist?

van Prooijen: Not the topic, but the method — the way you collect evidence and do your research. Do you get stuck in the idea that your theory must be true and shove aside all the evidence to the contrary? Or do you keep an open mind and stay open to the possibility that your initial suspicions were wrong, that maybe there is nothing going on? I think that is the key difference between a conspiracy theorist and someone who legitimately suspects corruption and investigates it.

There is an interesting point by Lewandowsky and colleagues (8): the most committed conspiracy theorists are actually very bad at detecting real corruption. That makes sense to me. If you believe in the wildest conspiracy theories — that shape-shifting reptilian elites secretly rule the world, say — that suggests your epistemic method is flawed. And the same flawed method will also make it harder to assess conspiracies that might actually be real.

The error nobody studies

Mukerji: Most studies look at people who already believe conspiracy theories and investigate how they think. What I would want to know is different. Take smart people and, to put it bluntly, dumb people, confront both with evidence, and see who correctly distinguishes a real conspiracy from a false one. Is there research like that?

van Prooijen: There have been quite a few studies using the cognitive reflection test. People who perform better on it are less likely to believe conspiracy theories (9). I also did a study with my colleague Thomas Ståhl looking at cognitive reflection and the motivation to be rational and rely on evidence (10). We found that lower conspiracy belief was associated with the combination of the two. In other words, to be less susceptible you need both the skill and the will to be rational.

Mukerji: But you can still load the dice if you only ask about very implausible conspiracy theories — the hollow earth, the lizard people. Has anyone tried to vary the epistemic quality of the theories?

van Prooijen: There is a scale called conspiracy mentality, a general tendency to believe that conspiracies are out there. The higher people score, the more likely they are to believe outlandish theories. But a recent study I really liked found that people who score very low are also more likely to underestimate genuine conspiracies (11). So you can be too naive.

Mukerji: Are researchers looking at the opposite problem as intensely — when people fail to recognize conspiracies or corruption that is actually there?

van Prooijen: No. That would be really interesting, but I haven’t looked into it.¹

Mukerji: But there are two mistakes you can make: disbelieving a conspiracy theory that is true, or believing one that is false. What is the correct balance?

van Prooijen: Type 1 and type 2 error, yes. That is a point we made in a 2018 paper with Mark van Vugt (12). Historically, the consequences of missing a conspiracy that was actually there may have been far more severe than those of believing in one that turned out not to be true.

That is error management theory: if one type of mistake is less costly than the other, we evolve to make the less costly one. I think that is what happened, at least in the past. Whether that balance still holds in modern society is a different issue.

The bearded loner who does not exist

Sevincer: What is the stereotype of a conspiracy theorist, and how accurate is it?

van Prooijen: The stereotype is a lonely guy with a long beard who still lives with his mother, out of a job, with no better things to do. It is largely inaccurate, because conspiracy theories can be found everywhere: among the rich and the poor, the highly and poorly educated, men and women. We typically find no gender effects at all.

At the same time, there can be a grain of truth in some stereotypes. Adversity in life – career failure, discrimination, social exclusion – is associated with stronger conspiracy belief (13). But the effects are too small to speak of a profile of the conspiracy theorist.

Sevincer: When I talk about this with friends, the response is often blunter: you have to be stupid to believe this. Is intelligence related?

van Prooijen: We have not looked at IQ directly, but we have looked at education. Less educated people are somewhat more susceptible, although the relationship is modest (14) and does not replicate everywhere. In some Middle Eastern countries the association was even reversed, possibly because education systems differ in the narratives they expose students to — for instance concerning whether Arabs were responsible for 9/11 (15).

And there are two caveats. Highly educated people can certainly believe conspiracy theories. And education may also make people better at rationalizing their beliefs – finding sources and articulating arguments that support what they already think.

Sevincer: Is believing in conspiracy theories pathological? You touch on this in your book: are these pathological processes, or exaggerated versions of processes we all have?

van Prooijen: Not necessarily pathological. Some forms of psychopathology — schizotypy, depression, schizophrenia, delusion proneness – are associated with stronger conspiracy belief (16). But we also compared more than 600 people with an autism diagnosis with a community sample of over 4,000 and found no difference in conspiracy mentality between these samples (17).

Sevincer: What had you expected?

van Prooijen: It was a sort of adversarial collaboration with a colleague who is an autism researcher. I thought autism might make people more vulnerable because social isolation can foster conspiracy thinking. He predicted the opposite: that autism would be protective because autistic people tend to score lower on empathizing – understanding other people’s mental states – but higher on systemizing – looking for rules and patterns in systems. I could see his reasoning. But: flat line.

The important point is that you do not need a mental disorder to believe conspiracy theories. People can have successful careers and still believe the wildest things.

Not a U-curve — a fish hook

Sevincer: Part of the stereotype is political. During the pandemic, “Corona is a hoax” was associated with the right. How are conspiracy beliefs actually distributed across the political spectrum?

van Prooijen: A couple of researchers, including me and Roland Imhoff, have found evidence for a U-curve: more conspiracy beliefs at both political extremes. Others found what the stereotype suggests – higher levels on the right, especially the far right.

Together with Imhoff I conducted a study, published in Nature Human Behaviour, across 26 countries and more than 100,000 participants (18). We found both. There is a U-curve, but it is asymmetrical – more like a fish hook, or Nike swoosh. Conspiracy belief is higher on the far left than in the center, but highest on the far right.

There is also considerable variation across countries. In some countries such as Spain conspiracy belief is more common on the left. And it matters what you mean by political ideology. We found essentially no relationship with economic left versus right, but a much stronger relationship with the sociocultural dimension — particularly right-wing views emphasizing protection of one’s country and culture from immigration. So the pattern depends heavily on the country and its political culture.

Sevincer: Does the content differ as well? Are there typically right-wing and typically left-wing conspiracy theories?

van Prooijen: Certainly. “COVID is a hoax” is a typical right-wing example, although it is not entirely absent on the left. On the left, examples include claims that wars in the Middle East are fought for oil profits, that Donald Trump is a Russian asset, or that Republican officials deliberately flooded poor neighborhoods during Hurricane Katrina.

Some topics even have left- and right-wing versions. Climate change can be framed on the right as a hoax, while on the left suspicions can focus on companies or governments exaggerating how environmentally friendly their policies are. Sometimes such suspicions may be justified but they can also be exaggerated.

Another example is 9/11. On the far right, some theories have blamed Israel or Mossad for the attacks. On the left, others focused on the Bush administration, claiming it orchestrated or knowingly allowed the attacks to justify subsequent wars.

Sevincer: In your book you also mention a link between conspiracy thinking and populism.

van Prooijen: Populism is closely aligned with it. At its core is the idea that society is a struggle between corrupt elites and ordinary people. That naturally overlaps with conspiracy thinking, and our research supports this. In a study across 13 EU countries, we found this association everywhere, although it was stronger in Western than in Eastern Europe (19).

The accusations differ by ideology: on the far right, elites are often accused of favoring immigrants over their own people; on the far left, of exploiting ordinary people – for instance, large global companies paying unfairly low wages. But the underlying worldview — a struggle between elites and the people — is similar.

Connecting dots that are not there

Sevincer: What is going on psychologically when someone believes the moon landing was staged? You have to disregard quite a lot of disconfirming evidence.

van Prooijen: I think two fast, almost automatic processes are important: pattern perception and agency detection. We are inclined to connect dots and infer intentions — usually useful tendencies, but ones that can misfire. We can see relationships or deliberate agency where none exists.

Then there is proportionality bias: the tendency to expect a major event to have a correspondingly major cause. You saw that after the Kennedy assassination — the idea that a single shooter could not possibly have killed the most powerful man on earth. But why not? You just need to pull the trigger.

And then there are the slower, more reflective processes, particularly motivated reasoning. Once people are committed to the idea that a theory must be true, they may disregard contrary evidence, dismiss experts who disagree as unreliable, part of the conspiracy, or just dumb, and selectively embrace experts who support their view.

Minds built for a world that no longer exists

Sevincer: Given that conspiracy theories seem to have existed throughout history, could they have served some evolutionary function?

van Prooijen: I would say the underlying tendency is an evolved response. When you encounter groups — particularly powerful ones, ones you do not know well, ones you think might be able to hurt you — it makes sense to start off not trusting them and expecting the worst. In an ancestral environment that might have been life-saving. A proclivity towards conspiracy theories may be a leftover from the tendency not to trust groups that are different, and prejudice may be a remnant of the same thing. It comes from an ancestral past in which intergroup conflict was a common cause of death. That was the argument Mark van Vugt and I made in our 2018 paper (12).

Mukerji: So what was adaptive then may not necessarily be rational now?

van Prooijen: Exactly. People did not evolve to always find the truth or always be rational. People evolved to stay alive. Sometimes that means taking the safe option, even if it might be wrong.

Mukerji: That sounds similar to Gigerenzer’s concept of ecological rationality (20): heuristics can work well in one environment but poorly in another.

van Prooijen: Right. That is evolutionary mismatch. Our minds evolved in environments very different from modern society, so tendencies that may once have been adaptive can work poorly today. We think conspiracy thinking is one example of such a mismatch.

Sevincer: Do conspiracy theories still have a function today?

van Prooijen: They can. Think of wartime. If you are a citizen of Kyiv you may have conspiracy theories about Russia whose specific details are not always correct, but the overarching picture keeps alive the notion of who your enemy is and who might indeed fire missiles at your home. That could be an example where conspiracy thinking still has a protective function.

Beyond that there are psychological functions: making meaning, making sense of the world, simplifying a complex reality. And we have data showing that conspiracy theories can also simply be entertaining. People like exploring them as if life were one big mystery.

A cheap and effective tool for starting a war

Sevincer: Then let us talk about the dangers. There are episodes in recent history where this got out of hand, most notably the theory that the American election was stolen.

van Prooijen: I said conspiracy theories are entertaining. I never said they are harmless entertainment. The Capitol Hill riots are an excellent example of how conspiracy theories can stimulate violence, and they are associated more generally with radical tendencies and the justification of violence.

Wars also go hand in hand with conspiracy theories. Remember Putin’s rhetoric about the Ukrainian government: that it was a regime of Nazis committing genocide, and that NATO had laboratories for chemical and biological weapons in Ukraine. These were conspiracy theories articulated by Putin to justify the war.

Mukerji: So they function as justifications — as a causal factor.

van Prooijen: It is common for leaders to use conspiracy theories to justify wars, and we published a paper asking whether this actually works (21). It does: conspiracy theories can increase public support for war. In that sense, spreading them about a country you plan to attack can be a cheap and effective way to get public opinion on your side.

More generally, the Thomas theorem applies: if people believe something is true, they act as if it were true. If they believe vaccines contain microchips, they may refuse vaccination; if they see climate policy as part of a conspiracy, that will shape how they respond to it. Irrational beliefs can have very real consequences.

Sevincer: And then a real scandal comes along. The grain of truth in QAnon, people say, is the Epstein case.

van Prooijen: QAnon was about a huge paedophile ring of mostly Democratic politicians coordinating ritual child sexual abuse. When the Epstein files became accessible, the reaction was: you see, we were right. But much of what emerged was already known, and it remains unclear who participated, who knew and looked away, and who simply knew Epstein without knowing what he was doing.

The Epstein case shows that child sexual abuse can involve wealthy and connected people. But that is very different from the grandiose claim of a coordinated network run by the Democratic Party.

What skeptics should actually do

Mukerji: If you had to give one pointed answer: what is the one thing your research says people should know about conspiracy theories?

van Prooijen: Many conspiracy theorists claim to be critical citizens. So be critical of that online influencer as well — the one who makes everything look very simple, goes against all the experts and the consensus, and spreads the wildest theories. If you are really critical, be critical of that person too.

Mukerji: What people understand by being critical is rejecting something.

van Prooijen: That is what people think. But rejecting all the experts and sheepishly following an influencer is not being critical. That is being cynical.

Critical thinking means looking critically at the evidence. It can mean accepting good ideas and rejecting bad ones, and being able to explain why something seems plausible or implausible. “It’s a politician, so he’s lying” has nothing to do with critical thinking.

Mukerji: So what should we as skeptics do about conspiracy theories?

van Prooijen: I don’t think we should encourage people to either believe or disbelieve conspiracy theories. We should encourage people to think rationally. To be willing to change their minds, to be intellectually humble, and to recognize that first impressions can be wrong.

There will always be actual corruption and real conspiracies. What we want is a society in which people investigate legitimate suspicions when things really do seem fishy, but also recognize when conspiracy theories are damaging. We want to encourage rationality, not belief or disbelief.

How to argue with a conspiracy theorist — and the strangest theories he knows

Sevincer: How did you personally become interested in conspiracy theories? Have you ever believed one yourself? I had friends who did, and was intrigued by a few things myself when I was an adolescent — the Bermuda Triangle, the face on Mars, Castaneda. That is part of what made me interested in skepticism.

van Prooijen: With me it started with two good friends who believed in 9/11 conspiracy theories. What interested me was that they were nice guys with perfectly normal lives – not the stereotypical conspiracy theorists at all. They just believed these theories. How is that possible?

Do I believe in them myself? I think everyone does to some extent, and as we discussed, it does not always have to be irrational. After the 2016 election, for example, I was inclined to believe theories about Trump colluding with Russia. So we are all susceptible to some extent. It is not something exclusive to internet keyboard warriors.

Sevincer: Have you ever debated a conspiracy theorist? Is it a piece of cake?

van Prooijen: It is not a piece of cake. Don’t expect miracles. The most important thing is to maintain respect. Stay true to yourself, say that you disagree, but do it respectfully if you want the other person to seriously consider that they might be wrong. And make sure you know what you are talking about. If someone has all sorts of theories about vaccines and you don’t know how vaccines work, read up beforehand.

Mukerji: That is challenging because of the bullshit asymmetry principle. You can make something up on the spot, but checking it takes much longer.

van Prooijen: Right. Experts are cautious. When someone throws a supposed fact at them, their first reaction may be: Did I miss that publication? I need to look into it. To a third party that can look like losing the argument, but catching an expert off guard does not make a claim true.

Sevincer: Final question: your top three conspiracy theories in terms of sheer bizarreness?

van Prooijen: One of my favorites is in my new popular science book just coming out: a guest on the Alex Jones show once claimed that NASA already had people on Mars and was sending young girls there as sex slaves. That actually led to an official response by NASA, stating that they only had a rover on Mars.

Then flat earth, which I still cannot wrap my head around. One US survey found about two per cent who believed the earth was flat, while another seven percent said they were not sure (22). Not sure!

And third, the alien lizards. What fascinates me is that it is so completely obvious where it comes from: a science-fiction series called V. Reptilian aliens disguised as humans come to control humanity. People took something from fiction and proclaimed it true.

Author Literatur Endnotes

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Prof. Dr. Jan-Willem van Prooijen

is a behavioral scientist and professor specializing in radicalization, extremism, and conspiracy thinking. He works at Vrije Universiteit Amsterdam, the Netherlands Institute for the Study of Crime and Law Enforcement (NSCR), and Maastricht University.

His research mainly focuses on conspiracy theories, unethical behavior, and radical ideologies, examining their role in politics and society. Van Prooijen has published numerous scientific articles and several books, including The Psychology of Conspiracy Theories (2018) and HOAX (2024).

He has received several awards for his research. He is also involved with various international academic journals and regularly appears as an expert in Dutch and international media.

His website: https://www.janwillemvanprooijen.com/

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1 Shortly after the interview was conducted, Robson et al. (2026) published a study examining people’s accuracy in distinguishing between verified conspiracies and unverified conspiracy theories. Jan-Willem van Prooijen subsequently drew our attention to the paper.

Robson, S. G., Martire, K. A., Pearson, S., Cosgrove, T. J., Jetten, J., Faasse, K., & Hornsey, M. J. (2026). Rejecting conspiracies doesn’t necessarily mean that you’re smart: The relationship between conspiracy discrimination and reasoning ability. British Journal of Social Psychology, 65, e70117.

Two ways to be wrong: The psychology of conspiracy beliefs