Much has been written on the positive aspects of cognitive fluency (in terms of typography, accents, and almost everything else), but a recent study (pdf, doi) suggests that the opposite (cognitive disfluency) could lead to better learning. The theory is that harder-to-process material requires “deeper processing” and that this deeper processing leads to superior memory performance.

Earlier this year the ever-excellent Jonah Lehrer summarised the study, describing how long-term learning and retention improved when classroom material was set in a hard-to-read font (e.g. Monotype Corsiva, Comic Sans Italicized or Haettenschweiler).

This study demonstrated that student retention of material across a wide range of subjects (science and humanities classes) and difficulty levels (regular, Honors and Advanced Placement) can be significantly improved in naturalistic settings by presenting reading material in a format that is slightly harder to read…. The potential for improving educational practices through cognitive interventions is immense. If a simple change of font can significantly increase student performance, one can only imagine the number of beneficial cognitive interventions waiting to be discovered.

One of the study authors, in a comment published in a New York Times article looking at cognitive fluency in learning, emphasises how it’s not the font that matters, but the processing difficulty:

“The reason that the unusual fonts are effective is that it causes us to think more deeply about the material, […] but we are capable of thinking deeply without being subjected to unusual fonts. Think of it this way, you can’t skim material in a hard to read font, so putting text in a hard-to-read font will force you to read more carefully.”