Words in larger font are perceived as more important: explaining the belief that font size affects memory

Words presented in larger font size are considered more memorable and rated with higher judgments of learning (JOLs). One explanation for this phenomenon is that people believe that font size affects memory. However, it is not clear why people hold this belief. One alternative is that font size represents importance, with larger fonts implying more relevant information. More important information is judged as more memorable and is, in fact, better remembered. In Experiments 1 and 2 we presented words in small (18 points) and extra-large font (250 points) and found higher JOLs and higher judgments of importance with extra-large fonts. A mediation analysis showed that importance accounted for 21-23% of the effect of font size on JOLs. In Experiment 3, we tested whether processing fluency was higher with the extra-large font. In a lexical decision task, participants were slower at detecting words and non-words with extra-large than small font, which is the opposite of what the processing fluency hypothesis predicts. This result shows that the font-size effect persists even in conditions in which perceived fluency should be lower. In sum, this research explained the belief that font size affects memory because words in larger fonts are considered more important.
This study was conducted at the Psychology Research Centre (PSI/01662), University of Minho, and supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, Technology, and Higher Education through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653).