Dems: Beware the Illusory Truth Effect

Repeating lies — even to debunk them — increases their believability

The Illusory Truth Effect is a cognitive phenomenon in which the repetition of information increases belief in its truth, even if the information is false and contradicts prior knowledge. People are more likely to believe something is true if it has been repeated, even if they have only heard it once before, and each time it is repeated, they are more likely to believe it’s true.

This phenomenon has what psychologists call a “built-in paradox.” The illusory truth effect is such a powerful phenomenon that it occurs even in cases when false information is being repeated in an effort to fact-check or debunk it. It has been observed in exposure to false information days, weeks, and months apart. And studies have shown that analytical thinkers and subject matter experts are not immune. In other words, even smart and knowledgeable people are vulnerable to this phenomenon.

This happens because of two simple hacks your brain uses to make its job easier: Hebbian plasticity and processing fluency. Hebbian plasticity is one of the first concepts students learn in an introductory neuroscience course because it’s the foundation of learning and memory: neurons that fire together, wire together. Put more simply, when the same neural pathways are activated over and over, the connections (or synapses) between them get stronger. For example, you have seen pumpkins in October many times throughout your life, so you know that pumpkins mean it is Fall. The neural pathways that represent pumpkins and Fall in your brain are very strongly connected. 

So what does this have to do with the illusory truth effect? Well, when the synaptic connections are stronger, it’s simply easier for your brain to process that information. Seeing a pumpkin and thinking about Fall takes no effort at all; it’s automatic. This is known as processing fluency: the ease with which your brain is able to process information. And here’s where it all comes together — the easier it is for your brain to process information, and the higher the processing fluency, the more likely your brain is to believe it is true. It doesn’t matter what the association is: the more that something is repeated, the stronger the synaptic connections, the higher the processing fluency, and the more you believe it to be true.

You can see how this poses a very real threat in the burgeoning era of disinformation. The repercussions of repeating falsehoods reverberate across our media and our politics. Far right wing actors hijack our brains to spread lies that fuel their agenda. And social media platform algorithms continue to feed people more of the same type of content over and over, pushing people deeper and deeper into their filter bubbles, where they become fervent believers of the lies they hear. It’s just how our brains are designed to work.

Propaganda feeds conspiracy theories. Conspiracy theories stoke fear. Fear leads to scapegoating. Scapegoating leads to anger. Anger turns to hate. The lies are repeated by those who believe them and by those who are trying to debunk them. The cycle repeats, and false information continues to spread. The trap is set.

Democrats are particularly vulnerable to stepping in these traps, because Donald Trump’s primary strategy is to peddle lies that will divide and distract the American people from the future he has in store for them, should he win the election. And Democrats, often with the best of intentions, make things even worse by refuting and debunking his lies. Nearly every time they say something Trump has said is not true, they repeat the falsehood, strengthen the neural pathways, make it easier for our brains to process, and increase the falsehood’s believability in people’s minds. 

We saw a prime example of this strategy in action on the presidential debate stage a couple of weeks ago. We won’t repeat what he said…because…you know. And you know even if you didn’t watch the debate because in the week that followed, Democrats went bananas creating memes and GIFS and even digital ads (again, we’re not linking) repeating his lies about immigrants in an effort to mock him and the absurdity of his comments.

They stepped right into the trap: they repeated and repeated and repeated his lies. And while it’s hard to lay blame with Democrats (for it certainly belongs with Donald Trump and J.D. Vance), their repetition of Donald Trump’s lies may have contributed to a growing belief that they are truthful. Such beliefs aren’t just wrong and bad; they pose real danger, as evidenced by the recent bomb threats in Springfield, Ohio.

So our message to Democrats is this: No matter how tempting, do not repeat the lies. Even in an effort to debunk or fact-check. Instead, point to the opposition’s strategy. Speak to their intent. Expose their motivation for saying such things. Then move the conversation back to our values and our shared vision for the future.

Donald Trump’s lies will continue. They will become more flagrant. They will become more frequent. They will be racist, sexist, transphobic, and xenophobic. Journalists will report on them. His supporters will repeat them. He will continue to conflate the issue of immigration with the issue of crime, and tempt Democrats to reinforce his narrative as they try to respond to both, rather than holding to the truth that these issues are distinct from one another. He will make statements that contain multiple falsehoods in an attempt to lure Democrats into a trap where they both repeat his lies in an effort to refute them and continue the conversation on his terms. 

Do not take the bait. 

This piece was co-written by Kate Catherall, founder of Slow Clap, and Dr. Jiggy Geronimo, founder of JG Insights.