What Is Cognitive Fluency and How It Affects Influence

“It is simplicity that makes the uneducated more effective than the educated when addressing popular audiences.” – Aristotle

What is Cognitive Fluency?

Our brains prefer simpler stimulus or information. Stimulus or information that is easier to process is called more fluent, hence the term processing or cognitive fluency. Essentially the less effort it takes for the brain to process the information, the “happier” it is. Conversely, when the stimuli challenge the brain, it thinks that it has problems because the information is unreliable. The principle works with any stimulus that is used in influence and communication. For example, if an unreadable typeface challenges your brain, the brain will think that the information communicated by the typeface is unreliable.

Complex Writing Makes You Look Stupid and Unpersuasive

In a series of experiments, students were asked to read texts of varying complexity. The readers considered the authors of the more complicated texts to be less intelligent and their message less persuasive. These results would break the hearts of many corporate presenters and veteran lawyers who consistently “increased” their intelligence by making their language more complex.

Shares with Fluent Names Increase Your Profits

In another experiment, the researchers have found that shares with easily pronounceable names (e.g. Yahoo!) significantly outperformed shares with difficult names (e.g. Dugxtban HGB). Researchers calculated that if you had invested $1,000 in a share with easily pronounceable name, it would outperform the share with least pronounceable name by $333 in just one year.

Foreign Accent is Unpersuasive

In a more recent experiment, the researchers had two speakers – one native speaker and the other foreigner – reading the same text to the college students. The students were told that the speakers were merely asked to read the text and that it was written by someone else.

The students who listened to the non-native speaker found the information to be less persuasive. Here again, because the students had to put extra-effort to understand the speaker with the accent, their brain considered the underlying information less reliable.

Any Use for Complexity?

As a general rule, information that is easier to understand will also be more persuasive. Yet, some research shows that there are certain occasions when complex language is more persuasive.  For example, when your message has only weak arguments, complex and difficult language may create an impression of high expertise and so persuade your audience more. Such occasions, however, are rather exceptional.


As a general rule, it is a safe bet to make your messages as simple as possible.   As Einstein famously said, “everything should be as simple as possible, but no simpler.”