DOI: https://doi.org/10.58248/RR92

Overview

A conspiracy theory is an attempt to explain significant events as the result of a secret plot involving powerful groups acting in their own interests.

While documented examples of real conspiracies and institutional wrongdoing do exist, conspiracy theories differ in that they typically involve broader claims of wrongdoing that extend beyond the available evidence.

Understanding how conspiracy claims function and how they can be distinguished from evidence-based accounts of wrongdoing may assist parliamentarians when evaluating information, responding to constituents, and considering policy related to misinformation, public trust, and democratic resilience.

This briefing does not assess the truth of specific claims but outlines psychological research on patterns and impacts of conspiracy theories.

What is a conspiracy theory?

Although there are different definitions of conspiracy theories, all emphasise three elements:

  • an allegation of secret coordination
  • by an alleged powerful group
  • to achieve harmful or self-serving goals

Importantly, conspiracy theory scholars do not deny the existence of real conspiracies. Historical cases of covert wrongdoing, corruption, and abuse have been documented through investigative journalism, public inquiries, and legal proceedings. These cases demonstrate that secrecy and coordinated misconduct can occur.

However, conspiracy theories often have features that do not appear in documented conspiracies.

For example, conspiracy theories often propose that multiple events are orchestrated by a single, highly coordinated group operating with long-term strategic unity. They may assume this single group has substantial control of a range of different institutions over an extended period, for which systematic evidence is lacking.

In contrast, documented conspiracies typically involve a small number of specific participants, occur over a shorter timeframe, and are verified by expert consensus. Some modelling studies suggest that the likelihood of uncovering a conspiracy increases as the number of participants grows, making large, all-encompassing conspiracies unlikely.

How common are conspiracy theory beliefs?

Survey research in the UK and internationally suggests that it’s relatively common for people to believe in at least one conspiracy theory, although whether people endorse specific claims varies depending on the topic and how the claim is phrased.

Researchers sometimes distinguish between endorsement of specific claims and a broader “conspiracy mentality”, a general tendency to see events as driven by hidden forces.

It is expected that levels of endorsement vary across issues and may fluctuate during societal crises, such as pandemics or major political events.

Some researchers argue that conspiracy beliefs are no more prevalent today than in previous historical periods. Conspiracy thinking is not a uniquely modern phenomenon and there are many historical examples, although communication technologies such as the internet have expanded the channels through which conspiratorial claims can circulate and reach audiences.

Why do conspiracy theories matter for public life?

A growing body of research suggests that conspiracy theory beliefs have political and social consequences.

Studies have found that people who endorse conspiracy theories have lower trust in democratic institutions. Some research suggests that people who believe conspiracy theories participate less in conventional political activity (such as voting), but in different contexts, people with conspiracy beliefs may be more engaged in political action against elites.

Other studies report that people with conspiracy theory beliefs may be less likely to follow public health guidance during crises.

There is also evidence from surveys that strong endorsement of certain conspiracy theories (such as antisemitic conspiracy theories) is associated with greater acceptance of political violence. One survey also found that people with stronger conspiracy mentality were more likely to approve of harassing scientists, and experiments suggest that exposing people to conspiracy theories targeting specific groups also exacerbates their prejudice and discrimination towards the target group.

However, most people who endorse conspiracy beliefs do not engage in illegal or violent behaviour and it is not clear that conspiracy beliefs directly lead to violence. For example, underlying factors, such as perceptions of hierarchy in society, economic hardship, or how politically active they are, may make people more likely to believe conspiracy theories and to participate in violence.

How can conspiracy theories be identified?

The following features often appear in conspiracy theories. They are not diagnostic on their own, but when several are present together, they may indicate a conspiratorial narrative structure.

  • Attribution to secret, coordinated groups: Conspiracy theories typically claim that a powerful group is acting in deliberate coordination behind the scenes. Importantly, the group’s power is often perceived rather than objectively established. As a result, conspiracy narratives do not necessarily track real power and may instead target groups with little structural power (such as immigrants).
  • Assumptions of unified intent: They often assume that the powerful group coordinates consistent, long-term strategic planning across different institutions or events.
  • ‘Self-sealing’ reasoning: Conspiracy beliefs are often constructed in such a way that they are impossible to disprove. For example, if there is no documentation to prove a conspiracy, someone who believes the conspiracy theory may take it as proof that the powerful group had suppressed information.
  • Pattern amplification: Unrelated or weakly connected events may be interpreted as part of a single hidden plan. Research shows that humans are predisposed to detect patterns, including in ambiguous or random information.
  • Selective use of evidence: Conspiracy narratives frequently rely on anecdotal accounts, cite experts selectively or emphasise isolated data points without broader contextual evidence.

However, these characteristics do not automatically invalidate a claim. Whether a claim of conspiracy is valid depends not on whether powerful actors are able to coordinate, but on the scope of the claims and the quality and independence of supporting evidence.

Investigations into real conspiracies can also begin with allegations of secrecy. However, evidence-based inquiries rely on verifiable documentation, independent corroboration, and transparent evaluation methods.

Why do people believe conspiracy theories?

People believe conspiracy theories for many different reasons and there is no single psychological profile of someone who believes in conspiracy theories. The journeys into conspiracy theorising are more complicated than a single profile.

Research suggests that conspiracy beliefs are associated with a combination of psychological, social and political factors. These factors all interact, and it can be difficult to establish what factors cause what effects.

This suggests that addressing conspiracy theories solely by correcting individual claims may not be effective as it overlooks the broader conditions that make conspiratorial narratives appealing.

Psychological factors

Studies indicate people believe conspiracy theories when their psychological needs are frustrated, for example, because they do not feel informed, secure and socially valued, or because they experience uncertainty, threat, or reduced feelings of control.

Some experiments have found that if people are temporarily made uncertain about a situation it can make them more receptive to conspiratorial explanations. Some researchers argue that such explanations provide clear, intentional accounts of events, which may be appealing when situations are complex or rapidly changing.

However, research suggests that conspiracy beliefs may not ultimately satisfy these psychological needs and may be associated with increased uncertainty or anxiety.

Trust and political context

Research has consistently found that people with lower trust in government, media, and other institutions are more likely to endorse conspiracy theories. Other research suggests that people might be more likely to believe conspiracy theories if they feel their social or political group is unfairly treated or threatened.

When people perceive political systems as unfair or corrupt, conspiratorial explanations may appear more plausible. However, distrust may arise from diverse experiences, and conspiracy beliefs should not be equated with legitimate political criticism or opposition.

Information environments

Online information environments might spread or reinforce conspiracy beliefs in a couple of ways.

First, digital platforms allow rapid circulation of information, which means people are often exposed to the same statements multiple times online, including unverified claims. When people are repeated exposed to a statement it can make them more likely to think it’s true, a phenomenon known as the “illusory truth” effect.

Second, online communities may reinforce shared interpretations. For example, discussions within a group may repeatedly highlight information that supports a particular interpretation of events while downplaying or questioning contradictory evidence.

However, current evidence does not clearly indicate that the internet or social media has increased conspiracy beliefs more than in previous historical periods. Conspiracy theories online might not “persuade” as much as “reinforce” existing views. Evidence regarding the precise influence of algorithms and platform design on conspiracy thinking continues to develop.

What techniques can help address a person’s conspiracy beliefs?

There is limited evidence on what large-scale interventions might help address conspiracy beliefs across large groups of people, and whether someone responds to an intervention and changes their beliefs may depend on context.

However, there is more evidence about what works when engaging with a single person who holds conspiracy beliefs. Researchers have developed evidence-based conversation prompts to use in these situations. These centre on:

Research suggests that simply providing corrective information may not always change strongly held beliefs. Conspiracy theories are persuasive and often playing on people’s feelings and sense of identity. Providing corrective information also does not address the possible root causes of the belief.

What are the limits of the current evidence on conspiracy beliefs?

Most research on conspiracy beliefs relies on surveys, where people are asked about their beliefs. Survey evidence can be limited because responses reflect self-reported beliefs at a particular moment and may not capture how strongly those beliefs are held or how they influence behaviour. Survey responses are also sensitive to how the survey is designed (such as how the question is framed) and the political context.

There are some experimental studies about conspiracy beliefs, but while they can test short-term changes in attitudes, they may not capture long-term belief formation.

There is comparatively limited UK-specific longitudinal evidence examining how conspiracy beliefs change over time and how they interact with policy interventions. Researchers also debate how best to distinguish between healthy scepticism and conspiratorial thinking.

Key questions for UK Parliament:

  • How robust is UK evidence on the prevalence and impact of conspiracy beliefs?
  • What evidence exists on effective responses?
  • How should policymakers balance countering harmful misinformation with protecting freedom of expression?
  • What role might digital regulation play in countering harmful conspiracy theories?
  • What role do transparency and institutional trust play?

For more information, please see our 2023 POSTnote briefing on Disinformation: sources, spread and impact.

Acknowledgements

Dr Daniel Jolley is an Associate Professor in Social Psychology at the University of Nottingham, specialising in the psychology of conspiracy theories. His research explores why conspiracy theories are appealing to many people, examines their social consequences, and develops strategies to reduce their negative effects.

Questions about this briefing should be referred to Oliver Bennett MBE, who acted as parliamentary lead for this work.