Within Rumours
Did that really cause this?
A rumour can feel explanatory when it links two events by timing, but sequence alone does not prove cause.
On this page
- Why timing feels persuasive during stress
- What causal evidence needs beyond sequence
- How health scares turn weak causes into action
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Introduction
When an alarming event occurs, people often want an explanation immediately. A sudden illness, a disaster, a death, a technological failure, or an unexpected cluster of symptoms can create a vacuum of uncertainty. Into that vacuum, rumours frequently supply a simple answer: one event happened first, therefore it must have caused the second. This is the false cause fallacy, often known as the post hoc fallacy—“after this, therefore because of this”. The reasoning feels persuasive because the timing is real, but timing alone does not establish a causal connection. [PMC]pmc.ncbi.nlm.nih.govPMCPost hoc ergo propter hocPMC - NIHby L Grouse · 2016 · Cited by 10 — This faulty reasoning is the most common cause of false and misleading conclusions of researc… [scribbr]scribbr.compost hoc fallacyDefinition & Examples8 May 2023 — The post hoc fallacy is the assumption that because one event preceded another event, they must be caus… Within rumours and unverified claims, false-cause thinking is especially powerful because frightening events create pressure for immediate explanations before investigators, scientists, journalists, or authorities have gathered enough evidence to determine what actually happened. The result is often a story that feels explanatory long before it is supported by evidence.
Why timing feels persuasive during stress
Human beings are naturally pattern-seeking. In ordinary life this is useful: identifying causes helps people avoid danger and make decisions. During crises, however, the same tendency can become a source of error.
After an alarming event, several psychological pressures converge:
- Uncertainty becomes uncomfortable. People prefer a simple explanation to having no explanation at all.
- Recent events are highly visible. Anything that happened shortly before the event attracts attention.
- Threats encourage rapid judgement. Waiting for evidence can feel risky when people believe danger is immediate.
- Stories spread faster than investigations. Rumours can circulate within minutes, while reliable causal analysis may take days, weeks, or months. World Health Organization [PMC]pmc.ncbi.nlm.nih.govPMCPost hoc ergo propter hocPMC - NIHby L Grouse · 2016 · Cited by 10 — This faulty reasoning is the most common cause of false and misleading conclusions of researc…
A rumour therefore gains traction through a familiar pattern:
- Event A occurs.
- Event B occurs soon afterwards.
- People infer that A caused B.
The leap from sequence to causation is the fallacy. The fact that one event preceded another is a clue that may deserve investigation, but it is not proof. [PMC]pmc.ncbi.nlm.nih.govPMCPost hoc ergo propter hocPMC - NIHby L Grouse · 2016 · Cited by 10 — This faulty reasoning is the most common cause of false and misleading conclusions of researc… [scribbr]scribbr.compost hoc fallacyDefinition & Examples8 May 2023 — The post hoc fallacy is the assumption that because one event preceded another event, they must be caus… This mechanism becomes especially persuasive when the consequence is dramatic. Research on crisis communication and attribution shows that people strongly seek someone or something to hold responsible when faced with harmful outcomes, often before sufficient evidence is available. [OUCI]ouci.dntb.gov.uacation articles in crisis situations, showing that responsibility attribution can be…Read more…
What causal evidence needs beyond sequence
A genuine causal claim requires more than “this happened first”.
Investigators typically look for several kinds of evidence before concluding that one event caused another:
A credible mechanism
There should be a plausible explanation for how the alleged cause produces the effect.
If a rumour claims that a particular exposure, technology, medicine, or action caused a harmful outcome, researchers ask whether any known biological, physical, or social mechanism connects the two events. A mere temporal relationship is not enough. [Iris]iris.who.intIris CAUSALITY ASSESSMENT OF AN ADVERSE EVENTIRISby World Health Organization · 2018 · Cited by 260 — Temporal relationship is consistent but there is insufficient definitive evidenc…
Consistent patterns
Real causes tend to produce effects repeatedly, not just in isolated anecdotes.
If an event truly causes a problem, similar outcomes should appear more often among exposed groups than among unexposed groups. One dramatic story may attract attention, but causal conclusions usually require broader evidence. [Vaccine Safety Institute]vaccinesafety.eduVaccine Safety InstituteMonitoring Vaccine SafetyMay 29, 2025 — Healthcare seeking bias creates a spurious association between vaccines a… [New England Journal of Medicine]nejm.orgNew England Journal of MedicineUnderstanding Vaccine Safety and the Roles of the FDA…by HC Meissner · 2022 · Cited by 38 — However, al…
Alternative explanations
Investigators must consider competing causes.
Many alarming events have multiple possible explanations. Illnesses occur naturally. Equipment fails for many reasons. Coincidences happen in large populations every day. A valid causal assessment asks whether the proposed cause explains the evidence better than the alternatives. [PMC]pmc.ncbi.nlm.nih.govPMCPost hoc ergo propter hocPMC - NIHby L Grouse · 2016 · Cited by 10 — This faulty reasoning is the most common cause of false and misleading conclusions of researc… [Iris]iris.who.intIris CAUSALITY ASSESSMENT OF AN ADVERSE EVENTIRISby World Health Organization · 2018 · Cited by 260 — Temporal relationship is consistent but there is insufficient definitive evidenc…
Statistical comparison
Anecdotes can suggest hypotheses, but they rarely establish causation.
For example, if millions of people experience a particular event, some unrelated illnesses or deaths will inevitably occur afterwards by chance alone. Determining causation requires comparing observed outcomes against what would normally be expected. [New England Journal of Medicine]nejm.orgNew England Journal of MedicineUnderstanding Vaccine Safety and the Roles of the FDA…by HC Meissner · 2022 · Cited by 38 — However, al… [Vaccine Safety Institute]vaccinesafety.eduVaccine Safety InstituteMonitoring Vaccine SafetyMay 29, 2025 — Healthcare seeking bias creates a spurious association between vaccines a…
How health scares turn weak causes into action
Health rumours provide some of the clearest examples of false-cause reasoning.
When a medical event follows a vaccination, medication, food exposure, or environmental change, people may immediately connect the two. Yet health authorities repeatedly distinguish between a temporal association and a causal association. An event occurring after a treatment does not automatically mean the treatment caused it. Iris ScienceDirect This distinction exists because large populations constantly experience illnesses [sciencedirect.com]sciencedirect.com· A temporal association is not equivalent to a causal association. · Our…Read more…, injuries, and deaths for many unrelated reasons. If millions receive a vaccine, some people will develop health problems shortly afterwards purely by coincidence. Determining whether the intervention increased the risk requires systematic investigation rather than anecdotal timing. [New England Journal of Medicine]nejm.orgNew England Journal of MedicineUnderstanding Vaccine Safety and the Roles of the FDA…by HC Meissner · 2022 · Cited by 38 — However, al… [CDC]cdc.gov04 Meyer COVID 508• Nationwide spontaneous reporting system that can rapidly detect safety signals, including rare events.Read more…
The World Health Organization’s framework for vaccine-event assessment explicitly notes that a consistent temporal relationship may exist even when there is insufficient evidence that the intervention caused the outcome. Additional evidence is required before causation can be established. [Iris]iris.who.intIris CAUSALITY ASSESSMENT OF AN ADVERSE EVENTIRISby World Health Organization · 2018 · Cited by 260 — Temporal relationship is consistent but there is insufficient definitive evidenc…
Because health outcomes are emotionally charged, false-cause rumours can spread rapidly. Reviews of health misinformation have found that misleading interpretations of health events can influence behaviour, increase anxiety, delay care, and contribute to vaccine hesitancy. World Health Organization [PMC]pmc.ncbi.nlm.nih.govPMCPost hoc ergo propter hocPMC - NIHby L Grouse · 2016 · Cited by 10 — This faulty reasoning is the most common cause of false and misleading conclusions of researc…
When alarming rumours produce real-world harm
False-cause rumours do not remain abstract reasoning errors. They can shape behaviour and public safety.
Recent reporting from the Democratic Republic of Congo described how rumours about a supposedly mysterious disease spread through communities and social media. The claims linked unrelated events into a causal narrative that health workers were somehow connected to the alleged threat. Investigations found no evidence that the illness was real, yet the rumours contributed to violence, including attacks on health workers. [Reuters]reuters.comFake rumors, real killings: Inside Congo's deadly health misinformation crisisThe panic led to violence, including the killing of four health workers conducting vaccination surveys. The WHO and Africa Infodemic Resp…
The broader lesson is not limited to one incident. During disasters, outbreaks, and emergencies, misinformation often thrives because people seek immediate explanations for frightening events. False causal stories can redirect blame, undermine trust in legitimate investigations, and motivate actions based on fear rather than evidence. [infodemiology.jmir.org]infodemiology.jmir.orgThe Impact of Misinformation on Social Media in the Context of…by S Hilberts · 2025 · Cited by 26 — Public confusion and fear are part… [World Health Organization]who.intWorld Health OrganizationInfodemics and misinformation negatively affect people's…1 Sept 2022 — Incorrect interpretations of health in…
The harm can take several forms:
- Avoidance of beneficial medical treatment.
- Misplaced blame directed at individuals or groups.
- Panic-driven decisions.
- Reduced trust in experts and institutions.
- Diversion of attention away from the actual cause. [World Health Organization]who.intWorld Health OrganizationInfodemics and misinformation negatively affect people's…1 Sept 2022 — Incorrect interpretations of health in… [World Health Organization]who.intWorld Health OrganizationInfodemics and misinformation negatively affect people's…1 Sept 2022 — Incorrect interpretations of health in…
A practical test for suspected causes
When encountering a rumour that claims an alarming event was caused by something that happened shortly beforehand, a useful question is:
What evidence supports causation beyond the fact that one event came first?
If the answer is little more than timing, the claim has not yet moved beyond the false-cause stage.
Stronger causal claims should be supported by a plausible mechanism, repeated observations, statistical evidence, investigation of alternatives, and independent verification. Until that evidence exists, the sequence of events may justify further inquiry, but it does not justify certainty. [ScienceDirect]sciencedirect.com· A temporal association is not equivalent to a causal association. · Our…Read more… [PMC]pmc.ncbi.nlm.nih.govPMCPost hoc ergo propter hocPMC - NIHby L Grouse · 2016 · Cited by 10 — This faulty reasoning is the most common cause of false and misleading conclusions of researc… [Scribbr]scribbr.compost hoc fallacyDefinition & Examples8 May 2023 — The post hoc fallacy is the assumption that because one event preceded another event, they must be caus…
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Endnotes
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Source: pmc.ncbi.nlm.nih.gov
Title: PMCPost hoc ergo propter hoc
Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC4958779/Source snippet
PMC - NIHby L Grouse · 2016 · Cited by 10 — This faulty reasoning is the most common cause of false and misleading conclusions of researc...
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Source: scribbr.com
Title: post hoc fallacy
Link: https://www.scribbr.com/fallacies/post-hoc-fallacy/Source snippet
Definition & Examples8 May 2023 — The post hoc fallacy is the assumption that because one event preceded another event, they must be caus...
Published: May 2023
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Source: pmc.ncbi.nlm.nih.gov
Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC9421549/Source snippet
and health misinformation: a systematic review of...by IJB do Nascimento · 2022 · Cited by 739 — This phenomenon, called an infodemic, i...
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Source: sciencedirect.com
Link: https://www.sciencedirect.com/science/article/pii/S1201971224000286Source snippet
· A temporal association is not equivalent to a causal association. · Our...Read more...
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Source: cdc.gov
Title: 04 Meyer COVID 508
Link: https://www.cdc.gov/acip/downloads/slides-2025-06-25-26/04-Meyer-COVID-508.pdfSource snippet
• Nationwide spontaneous reporting system that can rapidly detect safety signals, including rare events.Read more...
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Source: reuters.com
Title: Fake rumors, real killings: Inside Congo’s deadly health misinformation crisis
Link: https://www.reuters.com/business/media-telecom/fake-rumors-real-killings-inside-congos-deadly-health-misinformation-crisis-2026-05-07/Source snippet
The panic led to violence, including the killing of four health workers conducting vaccination surveys. The WHO and Africa Infodemic Resp...
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Source: infodemiology.jmir.org
Link: https://infodemiology.jmir.org/2025/1/e70413Source snippet
The Impact of Misinformation on Social Media in the [Context]({{ 'context/' | relative_url }}) of...by S Hilberts · 2025 · Cited by 26 — Public confusion and fear are part...
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Source: who.int
Link: https://www.who.int/europe/news/item/01-09-2022-infodemics-and-misinformation-negatively-affect-people-s-health-behaviours–new-who-review-findsSource snippet
World Health OrganizationInfodemics and misinformation negatively affect people's...1 Sept 2022 — Incorrect interpretations of health in...
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Source: iris.who.int
Title: Iris CAUSALITY ASSESSMENT OF AN ADVERSE EVENT
Link: https://iris.who.int/bitstream/handle/10665/259959/9789241513654-%20eng.pdf?sequence=1Source snippet
IRISby World Health Organization · 2018 · Cited by 260 — Temporal relationship is consistent but there is insufficient definitive evidenc...
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Source: vaccinesafety.edu
Link: https://www.vaccinesafety.edu/monitoring-vaccine-safety/Source snippet
Vaccine Safety InstituteMonitoring Vaccine SafetyMay 29, 2025 — Healthcare seeking bias creates a spurious association between vaccines a...
Published: May 29, 2025
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Source: nejm.org
Link: https://www.nejm.org/doi/full/10.1056/NEJMra2200583Source snippet
New England Journal of MedicineUnderstanding Vaccine Safety and the Roles of the FDA...by HC Meissner · 2022 · Cited by 38 — However, al...
-
Source: who.int
Title: disinformation and public health
Link: https://www.who.int/news-room/questions-and-answers/item/disinformation-and-public-healthSource snippet
World Health OrganizationDisinformation and public health6 Feb 2024 — Both misinformation and disinformation may cause harm, which compri...
Additional References
-
Source: researchgate.net
Link: https://www.researchgate.net/publication/320451737_Crisis_Management_and_Corporate_Apology_The_Effects_of_Causal_Attribution_and_Apology_Type_on_Publics%27_Cognitive_and_Affective_ResponsesSource snippet
The Effects of Causal Attribution and Apology Type on...9 Feb 2026 — This study examined how corporate apologies influence cognitive and...
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Source: medium.com
Link: https://medium.com/higher-neurons/the-post-hoc-ergo-propter-hoc-fallacy-5c8d4ceb568aSource snippet
The Post Hoc Ergo Propter Hoc Fallacy | by Myk EffThe “post hoc ergo propter hoc” fallacy is a common logical error that people commit wh...
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Source: pbs.org
Link: https://www.pbs.org/newshour/health/cdc-vaccine-safety-webpage-changed-to-contradict-scientific-conclusion-that-vaccines-dont-cause-autismSource snippet
CDC 'vaccine safety' webpage changed to contradict...20 Nov 2025 — The CDC "vaccine safety" webpage was updated Wednesday, saying "the s...
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Source: woah.org
Title: tackling misinformation to enforce efforts in global disaster risk reduction
Link: https://www.woah.org/en/article/tackling-misinformation-to-enforce-efforts-in-global-disaster-risk-reduction/Source snippet
Tackling misinformation to enforce efforts in disaster risk...13 Oct 2024 — The pandemic underscored the role that misinformation plays...
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Source: lib.uva.nl
Link: https://lib.uva.nl/permalink/31UKB_UAM1_INST/l6urij/alma9940364427205131Source snippet
uva.nl[https://lib.uva.nl/permalink/31UKB_UAM1_INST/l6uri...No](https://lib.uva.nl/permalink/31UKB_UAM1_INST/l6uri...No) information is available for this page...
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Source: ouci.dntb.gov.ua
Link: https://ouci.dntb.gov.ua/en/works/7XaDgRYr/Source snippet
cation articles in crisis situations, showing that responsibility attribution can be...Read more...
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Source: academia.edu
Link: https://www.academia.edu/340558/Attribution_Theory_As_a_Guide_for_Post_Crisis_Communication_ResearchSource snippet
mmunication research, advocating for an evidence-based approach to crisis...Read more...
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Source: journalistsresource.org
Title: [fake news]({{ ‘fake-news/’ | relative_url }}) conspiracy theories journalism research
Link: https://journalistsresource.org/politics-and-government/fake-news-conspiracy-theories-journalism-research/Source snippet
Fake news and the spread of misinformation: A research...1 Sept 2017 — This collection of research looks at the impact of fake news and...
-
Source: facebook.com
Link: https://www.facebook.com/NewsbookEN/posts/the-health-agency-stated-that-there-is-no-evidence-of-a-causal-relationship-with/3733034876782726/Source snippet
ture, the CDC stuff—temporal association does not prove causality.Read more...
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Source: scholar.google.nl
Link: https://scholar.google.nl/citations?hl=nl&user=yg39L5QAAAAJSource snippet
G.L.A. van der MeerPublic framing organizational crisis situations: Social media versus news media. TGLA Van der Meer, P Verhoeven. Publi...
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