When information is easy to process (fluent), we experience cognitive ease and are more likely to judge it as true, good, and safe.
In Depth
Cognitive ease is a feeling that System 1 uses as information. When processing is fluent—clear font, simple language, rhyming phrases, repeated exposure—we feel cognitive ease and judge the content as more true, more likeable, and less risky. This explains the illusory truth effect: repeated statements feel true because familiarity creates fluency. It also explains why clear writing is persuasive and why complex language reduces credibility. Cognitive ease is a metacognitive signal that System 1 interprets as evidence about the world.
Example
A statement in clear, simple font is judged as more true than the same statement in difficult-to-read font. Rhyming phrases ('woes unite foes') are judged as more insightful than non-rhyming equivalents ('woes unite enemies').
Common Misconception
Ease of processing is separate from truth—fluency is mistaken for truth, making repeated falsehoods feel increasingly true.