Symbol superiority: Why $ is better remembered than ‘dollar’

Memory typically is better for information presented in picture format than in word format. Dual-coding theory (Paivio, 1969) proposes that this is because pictures are spontaneously labelled, leading to the creation of two representational codes—image and verbal—whereas words often lead to only a single (verbal) code. With this perspective as motivation, the present investigation asked whether common graphic symbols (e.g.,!@#$%&) are afforded primarily verbal coding, akin to words, or whether they also invoke visual imagery, as do pictures. Across four experiments, participants were presented at study with graphic symbols or words (e.g., $ or ‘dollar’). In Experiment 1, memory was assessed using free recall; in Experiment 2, memory was assessed using old-new recognition. In Experiment 3, the word set was restricted to a single category. In Experiment 4, memory for graphic symbols, pictures, and words was directly compared. All four experiments demonstrated a memory benefit for symbols relative to words. In a fifth experiment, machine learning estimations of inherent stimulus memorability were found to predict memory performance in the earlier experiments. This study is the first to present evidence that, like pictures, graphic symbols are better remembered than words, in line with dual-coding theory and with a distinctiveness account. We reason that symbols offer a visual referent for abstract concepts that are otherwise unlikely to be spontaneously imaged.