The SNARC effect is not a unitary phenomenon: Individual variation in space-magnitude associations across domains

English speakers respond more quickly to small numbers with a leftward response and large numbers with a rightward response, a phenomenon known as the spatial-numerical association of response codes (SNARC) effect. Two prevailing theories to explain the SNARC effect make contrasting predictions about individual variability. If the SNARC effect stems from stable long-term memory representations, participants in a culturally homogeneous population (e.g., college students in a Western, English-speaking country) should exhibit a culturally consistent left-to-right SNARC with low variability between individuals within a magnitude domain and within individuals across domains. Alternatively, if the effect arises from an online working memory strategy, participants may be expected to show greater variability both between and within individuals, across and within domains. We present the results of three within-subject experiments in which participants engaged in multiple SNARC tasks across eight magnitude domains. Across the three experiments and 17 task presentations, we consistently found substantial variation in the orientation of the relationship between magnitude and space, both within a magnitude domain and across domains, in a culturally homogeneous Western sample. These findings are more consistent with accounts positing a flexible, context-dependent strategy than with those proposing a stable mental number line as an explanation of the SNARC effect. (PsycInfo Database Record (c) 2026 APA, all rights reserved).