Why Do People Believe Conspiracy Theories?

In 1979 the psychologists Clark McCauley and Susan Jacques ran a study with a simple trick. They gave people a description of an assassination attempt and varied two details: whether the attempt succeeded or failed, and whether the target was a head of state or a minor official. Everything else in the story stayed the same. People who read about a successful attack on a powerful figure rated it far more likely to be the work of a conspiracy than people who read the identical story with a failed attempt on a minor official.

Nothing about the actual evidence changed. Only the size of the event did. That gap between what happened and how big the explanation needs to feel is now called proportionality bias, and it is one of several ordinary pieces of reasoning that make conspiracy theories reasonable to a mind that is not doing anything unusual.

The same pull shows up well beyond assassinations. A public figure's sudden death, a surprising election result, a disaster with a huge toll - in each case, an explanation that fits the scale of the consequence feels more satisfying than one that does not, even when the mundane explanation is the one the evidence actually supports. A small, ordinary cause behind a large, extraordinary outcome leaves a gap that a conspiracy is very good at filling, whether or not it is true.

Three Needs, Not One

In a widely cited 2017 review, Karen Douglas, Robbie Sutton and Aleksandra Cichocka grouped the psychological motives behind conspiracy belief into three families. The first is epistemic: a need to understand a confusing or uncertain world, which becomes sharper after an event that resists ordinary explanation. The second is existential: a need to feel safe and in control, which a random or senseless disaster can threaten. The third is social: a need to feel good about the group you belong to, often by blaming an outside group for a shared misfortune.

None of these motives is unusual or pathological. They are the same needs that make people read the news, lock their doors, and root for their own team. Conspiracy belief, on this account, is not a separate kind of thinking bolted onto normal psychology - it is normal psychology applied to a situation where the official explanation feels too small, too random, or too uncomfortable to sit with.

A Suspicion, Not Just a Belief

A separate line of research asks a different question: not whether someone believes one particular theory, but whether they carry a general suspicion of the people who hold power. In 2014 Roland Imhoff and Martin Bruder measured this as "conspiracy mentality" - a standing tendency to assume that governments, corporations and other powerful institutions coordinate in secret against ordinary people's interests.

This generalized suspicion cuts across the political spectrum rather than sitting only on one side of it, and it is measurably distinct from attitudes such as right-wing authoritarianism or social dominance orientation, which track left-right politics much more closely. Someone high in conspiracy mentality does not need new evidence to reach for a conspiratorial explanation; the disposition is already there, waiting for an event to attach itself to. It also means that debunking one specific theory rarely changes much, because the theory was never really the point - the underlying suspicion was.

Do These Beliefs Actually Help?

Here is the part that most retellings of this research skip, and it is the most important part. Douglas, Sutton and Cichocka's review concludes that conspiracy beliefs generally fail to satisfy the very needs that drew people to them, and in some ways make things worse. Being exposed to conspiratorial framing has been shown to immediately reduce people's sense of autonomy and control, rather than restore it, and to make them less likely to take the ordinary actions - voting, getting vaccinated, staying engaged in political and civic life - that could actually improve their situation. The same research finds that exposure to conspiratorial claims tends to reduce trust in governmental institutions and breed disenchantment with the politicians and scientists meant to run them, eroding the very social trust that the social motive was reaching for in the first place.

That pattern - reaching for an explanation that promises control and belonging, and ending up with less of both - is the honest, uncomfortable center of this research. Conspiracy belief is also correlated with lower levels of analytic thinking and less formal education, but both links are modest, say nothing about any one person, and are only part of the picture. Alongside them, the size of the threat someone feels, how much uncertainty they can tolerate, and how much they already distrust the relevant institutions all help predict who reaches for a conspiratorial explanation.

What This Means for You

None of this is a reason to accept official explanations uncritically - some conspiracies, including well-documented historical ones like political cover-ups that were later confirmed by evidence and testimony, turned out to be true, and healthy skepticism of power is not the same disorder as conspiracy mentality. The distinction worth drawing is between skepticism that updates when good evidence appears, and a suspicion that treats absence of proof as proof of a better-hidden secret.

If a specific event - a public figure's death, an election, a disaster - has left you drawn toward a conspiratorial explanation, it can help to notice the shape of the pull rather than only the content of the theory: is the appeal that it explains something, that it restores a sense of control, or that it makes a group you dislike look guilty? Our conspiracy thinking test gives a rough read on where you currently sit, the need for closure test looks at how uncomfortable you find open questions in general, and the intellectual humility test looks at a trait that, across this literature, tends to sit on the more resistant side of the ledger.