Why do we think some things are related when they aren’t?

Illusory Correlation

, explained.
Bias

What is illusory correlation?

Illusory correlation, also known as illusory correlation bias, is the tendency to perceive a relationship between two variables when none actually exists. This cognitive bias often arises because the association aligns with our expectations or is amplified by the distinctiveness of certain events, making them more memorable and salient in our minds.

Where illusory correlation is seen

Consider the following hypothetical situation: Jane is an avid football fan and watches every game that her beloved “Guardians” play on live television. Jane always wears her tattered Guardians jersey while watching their games— the same one she has worn for years.

According to Jane, it is vital that she wear her “lucky jersey.” The success of her team depends on it. A few years earlier, Jane had noticed that when she didn’t wear her jersey, the Guardians lost. This phenomenon happened a few times before Jane’s superstitions were solidified. Now, she is certain: the success of her favorite football team is in some way related to her wearing this jersey.

Jane’s false perception that wearing her jersey at home is directly related to the performance of her favorite football team can be attributed to an illusory correlation. 

Cartoon of Jane in her jersey talking to a friend. Jane says 'I have to wear my lucky jersey because if I don't they lose' and the friend says 'what if you wear it and they do lose?'

Illusory correlation is a cognitive bias that is closely linked to memory and perception, as people tend to notice and remember patterns or associations that confirm their expectations or stand out in some way. Sometimes, our decisions hinge on the relationship between various phenomena—for example, when I do “Y,” I know “X” will occur. We see that certain events consistently occur at the same time as, or just after, other events, leading us to conclude that they are somehow related. We may not know why they are related, but we have enough evidence to suggest that their occurrence is linked. 

Mis- and disinformation can also exacerbate illusory correlations and lead to their widespread acceptance. If the public learns about a flawed correlation between two events or factors from an individual with authority, they are more likely to accept it as truth. In 2006, J. D. Hayworth, one of America’s most outspoken Congressmen, published a book called Whatever it Takes: Illegal Immigration, Border Security, and the War on Terror, in which he claimed that inflows of people over the U.S.-Mexico border posed a “terrorist threat.” Juxtaposing undocumented immigration with terrorism produces an illusory correlation because the majority of migrants entering the U.S. from the South are people in search of better career opportunities, not terrorists with ulterior motives.18 

We can’t always know if and why two things are causally related. Sometimes, it’s enough to know that they are somehow related. If we see this relationship occur many times, we become confident that the correlation will reliably recur in the future. 

Related Biases

Sources

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  2. Hyman, I. (2015, June 21). Race, Violence, and Illusory Correlations. Retrieved July 19, 2020, from https://www.psychologytoday.com/ca/blog/mental-mishaps/201506/race-violence-and-illusory-correlations
  3. Ousey, G. C., & Kubrin, C. E. (2018). Immigration and Crime: Assessing a Contentious Issue. Annual Review of Criminology, 1(1), 63-84. doi:10.1146/annurev-criminol-032317-092026
  4. Illusory Correlation (SOCIAL PSYCHOLOGY) – iResearchNet. (2016, January 21). Retrieved July 19, 2020, from https://psychology.iresearchnet.com/social-psychology/decision-making/illusory-correlation/
  5. Tversky, A., & Kahneman, D. (1973). Availability: A heuristic for judging frequency and probability. Cognitive Psychology, 5(2), 207-232. doi:10.1016/0010-0285(73)90033-9
  6. Munro, G. D., & Stansbury, J. A. (2009). The Dark Side of Self-Affirmation: Confirmation Bias and Illusory Correlation in Response to Threatening Information. Personality and Social Psychology Bulletin, 35(9), 1143-1153. doi:10.1177/0146167209337163
  7. Matute, H., Yarritu, I. and Vadillo, M.A. (2011), Illusions of causality at the heart of pseudoscience. British Journal of Psychology, 102: 392-405. doi:10.1348/000712610X532210
  8. Illusory correlation. (2015). Retrieved July 20, 2020, from https://www.oxfordreference.com/view/10.1093/acref/9780199657681.001.0001/acref-9780199657681-e-405
  9. Fiedler, K., Hemmeter, U., & Hofmann, C. (1984). The Origin of Illusory Correlations. European Journal of Social Psychology.
  10. Barbera, F. L. (2015). Educating to Tolerance: Effects of Communicating Social Psychology Research Findings. Europe’s Journal of Psychology, 11(3), 476-483. doi:10.5964/ejop.v11i3.888
  11. Bender, J. C., Osler, C. L., & Simon, D. (2012). Noise Trading and Illusory Correlations in US Equity Markets*. Review of Finance, 17(2), 625-652. doi:10.1093/rof/rfr037
  12. Kolev, G., & Hogarth, R. (2010). Illusory correlation in the remuneration of chief executive officers: It pays to play golf, and well. Department of Economics and Business, Universitat Pompeu Fabra.
  13. Cullell, J. M. (2022, September 20). What’s the probability of three earthquakes hitting Mexico City on the date September 19? El País. https://english.elpais.com/international/2022-09-20/whats-the-probability-of-three-earthquakes-hitting-mexico-city-on-the-date-september-19.html
  14. Mendonça, C. et al. (2024). The social amplification of illusory correlations. European Journal of Social Psychology, 54(7), 1489-1499. 
  15. Gaudiano, P. (2018, March 19). Five Reasons Why Recruiting Talent From Top Schools Is A Terrible Idea. Forbes. https://www.forbes.com/sites/paologaudiano/2018/03/19/recruiting-talent-from-top-schools-is-a-terrible-idea/
  16. Handy, L. (2024, February 5). Vaccines ad Autism. Children’s Hospital of Philadelphia. https://www.chop.edu/vaccine-education-center/vaccine-safety/vaccines-and-other-conditions/autism
  17. Gallagher, J. (2015, September 23). Childhood MMR vaccination rates fall. BBC News. https://www.bbc.com/news/health-34335509
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  20. Ignatans, D., & Matthews, R. (2017). Immigration and the Crime Drop: International Perspectives. European Journal of Crime, Criminal Law and Criminal Justice, 25(3), 205-229. 
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  25. Cazes, M., et al. (2021). Evaluation of the sensitivity of cognitive biases in the design of artificial intelligence. Rencontres des Jeunes Chercheurs en Intelligence Artificielle (RJCIA ‘21) Plate-Forme Intelligence Artificielle (PFIA ‘21), Jul 2021, Bordeaux, France. 30-37. 
  26. University of Leeds. (2023, July 20). Why price does not indicate how long clothes will last. University of Leeds. https://www.leeds.ac.uk/news-working-business/news/article/5346/why-price-does-not-indicate-how-long-clothes-will-last

About the Authors

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Dan Pilat

Dan is a Co-Founder and Managing Director at The Decision Lab. He is a bestselling author of Intention - a book he wrote with Wiley on the mindful application of behavioral science in organizations. Dan has a background in organizational decision making, with a BComm in Decision & Information Systems from McGill University. He has worked on enterprise-level behavioral architecture at TD Securities and BMO Capital Markets, where he advised management on the implementation of systems processing billions of dollars per week. Driven by an appetite for the latest in technology, Dan created a course on business intelligence and lectured at McGill University, and has applied behavioral science to topics such as augmented and virtual reality.

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Dr. Sekoul Krastev

Sekoul is a Co-Founder and Managing Director at The Decision Lab. He is a bestselling author of Intention - a book he wrote with Wiley on the mindful application of behavioral science in organizations. A decision scientist with a PhD in Decision Neuroscience from McGill University, Sekoul's work has been featured in peer-reviewed journals and has been presented at conferences around the world. Sekoul previously advised management on innovation and engagement strategy at The Boston Consulting Group as well as on online media strategy at Google. He has a deep interest in the applications of behavioral science to new technology and has published on these topics in places such as the Huffington Post and Strategy & Business.

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