Was the election rigged? Is the Earth actually flat? Was the COVID-19 pandemic planned? These conspiracy theories have been debunked, yet many still believe them. Why? The constant repetition of these claims makes it harder for people to think critically and assess the truth. 

Misinformation is the spread of false or misleading information, even though the person sharing it may not know it is false. Misinformation can result in small misunderstandings yet may also lead to large-scale consequences, such as political effects. The Illusory Truth Effect can be examined to understand the serious implications of misinformation when fueled by repetition. This is a cognitive bias that occurs when repeated exposure to information, whether true or false, increases its perceived truth.

The Illusory Truth Effect was tested in a study by Gordon Pennycook, Tyrone Cannon, and David Rand and published in the Journal of Experimental Psychology in 2018. The researchers aimed to investigate whether prior exposure to fake news headlines on social media could increase their perceived accuracy, even when people knew the information was false or implausible. They looked at how exposure to fake news during the 2016 United States Presidential Election affected people's belief in its accuracy. Participants were exposed to both fake and real news headlines and were asked to assess how true or false they thought the headlines were. There were 409 participants that completed the study, most of them adults, with an average age of 36, and diverse educational backgrounds.

Participants rated how interesting each statement was on a 6-point scale. Half of the statements were repeated, familiarizing the participants, while others were presented only once. Afterwards, participants assessed 12 statements for accuracy on a 6-point scale. The goal was to identify how repetition, whether prior exposure or novel, affected how the statements were perceived.

The results? Repetition of false statements significantly increased their perceived truth by participants. When people encountered fake news headlines multiple times, they were more likely to rate them as accurate, as opposed to if they had only heard them once. This theory is extremely relevant today as it reveals how repetition, especially on social media, where almost anything can be shared, can manipulate our beliefs. Even when something seems implausible, just seeing a few posts about it can make it feel true.

Furthermore, the best way to combat misinformation is awareness. The more we understand how our brains are influenced by repetition, the better equipped we are to resist believing false claims. It is imperative that we question, fact-check, and educate because The Illusory Truth Effect demonstrates that repetition is not just about familiarity but shapes our reality.