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THE QUESTION LIBRARY HOW WE KNOW
Why do some conspiracy theories spread so easily?
Real conspiracies have happened, so suspicion can be reasonable; here is why some theories spread so easily, and how to check one fairly.
THE SHORT ANSWER
Because they speak to ordinary human needs. Research suggests that people are drawn to conspiracy theories when they want to make sense of big events, feel safe and in control, and feel good about their group. In a large Twitter study, false stories spread faster than true ones, perhaps partly because they seemed new. Some suspicions are warranted: the CIA’s MKUltra drug tests and the Tuskegee syphilis study were real abuses. The fair test is evidence you can check, the way those cases came to light.
- A 2017 review sorted the motives linked to conspiracy belief into three kinds: understanding events, feeling safe and in control, and feeling good about oneself and one’s group.
- From 1953 to 1964, the CIA’s MKUltra project funded research on drugs and behavior, including drug tests on people who did not know they were being tested.
- From 1932 to 1972, a U.S. Public Health Service study followed 399 Black men with syphilis without their informed consent and did not offer them treatment.
- On Twitter from 2006 to 2017, false news spread farther and faster than true news, and people, not bots, drove the difference.
- Surveys tracking 46 conspiracy theories in the U.S., some for half a century, found no systematic rise in belief.
About this picture
The title page of Book II of the Church Committee’s 1976 final report. The Senate committee, led by a Democrat with a Republican vice chairman, documented real abuses by U.S. intelligence agencies, and scholars still use its reports today.
WHERE THE EVIDENCE STANDS
How sure are we?
- People are drawn to conspiracy theories by needs to understand events, to feel safe and in control, and to feel good about their group.Douglas, Sutton and Cichocka (2017) review: belief is linked to uncertainty, anxiety and powerlessness, and in experiments it fell when people’s sense of control was affirmed. The few studies of consequences do not show these theories meeting those needs, though they mostly tested students and survey panels rather than groups that already feel shut out; much of the wider research is correlational (Douglas and colleagues, 2019).
- Some government programs that deceived or harmed people were real, and came to light only years later.MKUltra: 1977 Senate hearing (a CIA project from 1953 to 1964, covert drug testing on unwitting citizens, the bulk of its records destroyed in 1973). Tuskegee: CDC (1932 to 1972, no evidence of informed consent, treatment not offered). Church Committee final report (1976): abuses by the CIA, FBI, IRS and National Security Agency.
- False stories spread farther and faster online than true ones.Vosoughi, Roy and Aral (2018): about 126,000 stories shared on Twitter from 2006 to 2017; false news was more novel, and bots spread true and false news at the same rate. This is one platform and one period, and it covers false news in general, so other settings may differ.
- Belief in conspiracy theories is rising.Uscinski and colleagues (2022): 46 U.S. conspiracy theories, some tracked across half a century, and six theories in six European countries; no systematic evidence of an increase (some beliefs rose, but more fell). Douglas and colleagues (2019), a review that Uscinski also co-wrote: no evidence that people are more prone to conspiracy thinking than before the internet.
- Short prebunking videos help people spot manipulation techniques.Roozenbeek and colleagues (2022): six experiments with 6,464 people and a YouTube field test with 22,632 answers; in the field test, recognition rose about 5% on average. The study could not measure how long the effect lasts, and it was funded by Google’s Jigsaw unit.
WHAT WE DON’T KNOW YET
Much of this research is correlational, so cause and effect are often unclear. Researchers still debate how much the internet spreads conspiracy belief, and the 2022 prebunking study could not measure how long its effect lasts.
WHAT WOULD CHANGE THIS ANSWER
Well-designed surveys showing that belief in conspiracy theories is rising would change part of this answer. So would long-term studies finding that conspiracy belief leaves people feeling safer, more in control and more connected; research so far has not shown this, though few studies have tested groups that already feel shut out.
Conspiracy theories spread easily because they speak to ordinary human needs: to understand what is happening, to feel safe and in control, and to feel good about the people we belong to. Researchers note that people are not always aware of these needs. Online, new and surprising false stories can move fast, though conspiracy theories often stay among people who already agree.
History also gives real reasons for suspicion. From 1953 to 1964, a CIA project called MKUltra funded research on drugs and behavior, including drug tests on people who did not know they were being tested. The bulk of its records were destroyed in 1973. From 1932 to 1972, a U.S. Public Health Service study at Tuskegee, Alabama, followed 399 Black men with syphilis without their informed consent and did not offer them treatment, even after it was widely available. Both cases are documented by the U.S. government itself.
So how do you tell a warranted suspicion from a theory that no evidence could ever count against? The real cases came to light through things anyone can check: documents, news reports, public hearings and a request for records under the Freedom of Information Act. A theory that treats evidence against it as part of the cover-up is much harder to test. Some philosophers suggest judging each theory on its own merits and asking how many people would have to keep quiet, and for how long.
There is good news, too. In studies with thousands of people, short videos that explain common manipulation tricks ahead of time, a method called prebunking, helped people spot those tricks. You are welcome here, whether you suspect a plot or doubt one.
THE LONG ANSWER
THE LONG ANSWER · ABOUT 7 MINUTES
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God Plays Dice answers big questions in plain words, with sources and one of six honest labels.
Words worth knowing (6)
- Conspiracy
- A hidden plot by two or more powerful people or groups. Real conspiracies happen, and some have been exposed.
- Conspiracy theory
- An explanation that says a hidden plot by powerful people or groups caused an important event. It may or may not be true.
- Unfalsifiable
- Built so that no evidence could ever show it wrong. Even evidence against the idea is counted as support for it.
- Prebunking
- Warning people about a misleading argument or technique before they meet it, so they can spot it later.
- Informed consent
- A process in which people are given the important facts about a study or treatment, including its possible risks and benefits, so they can decide whether to take part.
- Correlational study
- A study that finds two things go together without showing that one causes the other.
Sources & further reading
(9) · Checked Sep 29, 2026
- The Psychology of Conspiracy Theories (Douglas, Sutton and Cichocka) ↗Current Directions in Psychological Science 26(6):538–542 (2017)Open access (PMC5724570); authors at the School of Psychology, University of Kent. Conspiracy theories: “explanations for important events that involve secret plots by powerful and malevolent groups”; motives characterized as epistemic (understanding, accuracy, subjective certainty), existential (control and security) and social (positive image of self and group); belief stronger when people experience distress from feeling uncertain and for large-scale or significant events that leave mundane explanations unsatisfying; people turn to conspiracy theories when anxious and powerless; heightened when people feel unable to control outcomes and reduced when control is affirmed (van Prooijen and Acker 2015); ostracism raised belief (Graeupner and Coman 2017); theories are “resistant to falsification”, implying that people who try to refute them may themselves be part of the conspiracy; little research on consequences, and it “does not indicate that conspiracy belief fulfills people’s motivations”; exposure suppressed sense of autonomy and control and decreased trust in governmental institutions; “more appealing than satisfying”; caveat: the experiments sampled undergraduates and survey panelists who are not particularly disadvantaged, while for groups already alienated from society conspiracy belief “may offer an important source of belonging and shared reality”; “history has repeatedly shown that corporate and political elites do conspire against public interests. Conspiracy theories play an important role in bringing their misdeeds into the light.”
- Understanding Conspiracy Theories (Douglas, Uscinski, Sutton, Cichocka, Nefes, Ang and Deravi) ↗Political Psychology 40(S1):3–35 (2019)Open access (CC BY). Full published version read from the University of Kent repository copy (https://kar.kent.ac.uk/71278/11/Douglas%20et%20al%202019%20Political%20Psychology.pdf) and cross-checked against the DIGITAL.CSIC copy (http://hdl.handle.net/10261/369501). A conspiracy is a “secret plot by two or more powerful actors”; conspiracies such as Watergate “do happen” but tend to fail because of the difficulties of executing plans and keeping people quiet; a conspiracy theory is an allegation “that may or may not be true”; the labels can “neutralize valid concerns and delegitimize people”; believers “often turn to other conspiracy theories” to explain why a pet theory has no support (Boudry and Braeckman 2011; Keeley 1999); people “do not necessarily need to be conscious of these motives”; belief stronger under uncertainty (van Prooijen and Jostmann 2013); people on both sides of the left-right spectrum entertain conspiracy beliefs about the other side, while scholars disagree about whether they are more common on the right; New York Times letters to the editor 1890–2010: targets shift with which party holds the presidency (Uscinski and Parent 2014); “no evidence that people are more prone to conspiracy thinking now than they were prior to the invention of the Internet”; online, conspiracy theories “tend to stay concentrated within the communities who already agree with them” (Uscinski et al. 2018, as reported); in 9/11 comments (four mainstream news sites, 2011), opponents of the theory used a more hostile tone, which may feed believers’ sense of being a “bullied, principled minority” (Wood and Douglas 2013); some scholars argue conspiracy theories are a crucial instrument for holding authorities accountable; the authors argue the theories do more harm than good but “caution against a demonization” of believers; “much of the literature to date has been correlational”.
- Project MKULTRA, the CIA’s Program of Research in Behavioral Modification: Joint Hearing, August 3, 1977 ↗U.S. Senate Select Committee on Intelligence and Subcommittee on Health and Scientific Research (U.S. Government Printing Office, 1977)Hearing record (text layer of the Senate Intelligence Committee PDF). Prepared statement of Adm. Stansfield Turner, Director of Central Intelligence: MKULTRA “a closely held CIA project conducted from 1953-1964”, an umbrella project funding subprojects involving research on drugs and behavioral modification; the 1963 Inspector General report mentions covert testing on unwitting U.S. citizens; files destroyed in 1973; seven boxes of finance folders and related papers found at the Retired Records Center by an employee responding to Freedom of Information Act requests; 149 MKULTRA subprojects; 80 institutions named, including 44 colleges or universities; “cut-out” (intermediary) funding used to conceal CIA sponsorship; “Most of the people and institutions involved are not aware of Agency sponsorship”; the cryptonym became publicly known during the 1975 Rockefeller Commission and Church Committee investigations. Senator Edward Kennedy (chairman, Health Subcommittee): “At least one death … resulted from these activities”; records destroyed in January 1973 at the instruction of then CIA Director Richard Helms; “the bulk of the agency’s records were destroyed in 1973”; “one individual, through a Freedom of Information request, accomplished what two U.S. Senate committees could not.”
- About the Untreated Syphilis Study at Tuskegee ↗U.S. Centers for Disease Control and PreventionU.S. Public Health Service study conducted between 1932 and 1972 to observe the natural history of untreated syphilis; 399 men in the syphilitic group and 201 in the control group; limited to Black men 25 or older; community members were aware of the study but thought it was a special government health care program; no evidence that researchers obtained informed consent; participants not offered available treatments, even after penicillin became widely available; ended in 1972 on the recommendation of an Ad Hoc Advisory Panel convened following publication of news articles; 1997 formal Presidential Apology by President Clinton. Glossary definition of informed consent adapted from the NCI Dictionary of Cancer Terms (https://www.cancer.gov/publications/dictionaries/cancer-terms/def/informed-consent; text read through the NCI glossary API).
- Senate Select Committee to Study Governmental Operations with Respect to Intelligence Activities (Church Committee) ↗United States Senate1974 front-page New York Times article by Seymour Hersh “claiming that the CIA had been spying on anti-war activists”; resolution introduced January 21, 1975, approved 82-4; Democrat Frank Church chairman, Republican John Tower vice-chairman; identified “a wide range of intelligence abuses” by the CIA, FBI, IRS and NSA; COINTELPRO targets included the Southern Christian Leadership Conference, the anti-Vietnam War movement, Martin Luther King Jr., and local, state and federal elected officials; final report April 29, 1976: “intelligence excesses” were not the “product of any single party, administration, or man”; scholars still use the reports and hearings. The reports, including Book II (Report No. 94-755, the image on this page), are listed on the Senate Intelligence Committee’s page https://www.intelligence.senate.gov/resources/intelligence-related-commissions/.
- Conspiracy Theories (Marc Pauly) ↗Internet Encyclopedia of PhilosophyGeneralists vs particularists: particularists like Pigden hold that each conspiracy theory “needs to be evaluated on its own (de)merits”; Clarke: Watergate as a progressive research program (journalists’ successful predictions) vs the Elvis Presley fake-funeral theory as degenerating (no novel predictions that were confirmed); Keeley (2003): absence of evidence is not evidence of absence, but if diligent efforts fail where similar efforts in similar cases succeeded, lowering credibility is justified; more agents and longer duration make a conspiracy theory less likely (Hepfer, Keeley); Grimes (2016) simulations: conspiracies with 1000 agents or more unlikely to succeed; Basham and Dentith counter the scale argument (Dentith: when an institution is involved, only very few of its people are); proponents may have motives to lie or mislead, and so may people who reject a theory as “just” a conspiracy theory (Räikkä, Pigden).
- The spread of true and false news online (Vosoughi, Roy and Aral) ↗Science 359(6380):1146–1151 (2018)Abstract (PubMed 29590045): verified true and false news stories on Twitter from 2006 to 2017, about 126,000 stories tweeted by about 3 million people more than 4.5 million times; six independent fact-checking organizations (95 to 98% agreement); falsehood diffused farther, faster, deeper and more broadly, more so for political news; false news more novel; false stories inspired fear, disgust and surprise in replies; robots spread true and false news at the same rate, so humans drove the difference.
- Have beliefs in conspiracy theories increased over time? (Uscinski, Enders, Klofstad, Seelig, Drochon, Premaratne and Murthi) ↗PLOS ONE 17(7):e0270429 (2022)Abstract (PubMed 35857743) and full text (PMC9299316): Study 1, change in the share of Americans believing 46 conspiracy theories, some observations spanning half a century; Study 2, six European countries and six conspiracy theories; Study 3, beliefs about which groups conspire; Study 4, generalized conspiracy thinking in the U.S. from 2012 to 2021; “In no instance do we observe systematic evidence for an increase in conspiracism, however operationalized.” Full text: beliefs in 13 of 52 theories rose significantly, but decreases outnumbered increases and were larger; the study is limited to theories that earlier polls asked about. Uscinski is also a co-author of the 2019 review above.
- Psychological inoculation improves resilience against misinformation on social media (Roozenbeek, van der Linden, Goldberg, Rathje and Lewandowsky) ↗Science Advances 8(34):eabo6254 (2022)Open access (PMC9401631); first author at the Department of Psychology, University of Cambridge. Prebunking described as building resilience ahead of expected exposure to misinformation, with a forewarning and a preemptive refutation; five short animated videos made in partnership with Google Jigsaw, on emotionally manipulative language, incoherence, false dichotomies, scapegoating and ad hominem attacks; 1.5-minute videos; examples “nonpolitical and fictitious” and humorous “to avoid any appearance of partisan bias”; six randomized controlled studies (n = 6,464) and a YouTube field study (n = 22,632 responses, treatment vs matched control); improved technique recognition, confidence, discernment and sharing decisions, “robust across the political spectrum”; field study: videos shown to about 5.4 million YouTube users over 15 days, one test question within 24 hours, recognition up “about 5% on average”; limitations: could not study how long the effect lasts, U.S. audiences only; funded by Google Jigsaw. Videos page (https://inoculation.science/inoculation-videos/): a collaboration of Cambridge University, the University of Bristol and Google Jigsaw; “Research shows that using emotional words, especially ones that evoke negative emotions such as fear or outrage, increases the viral potential of social media content.”
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