Task-Dependent Sources of SNARC-Like Effects: A Controlled-Learning Study

The present study addressed two unresolved questions about SNARC-like effects: magnitude, ordinal position, and learned spatial associations often share the same left–right mapping, obscuring source-specific contributions, and it remains unclear whether their expression varies across judgment tasks. In a controlled-learning design, age magnitude and birth-order position predicted opposing mappings, whereas learned spatial location was orthogonal to both. Eighty-four adults participated in three independent samples (n = 28 each). Participants learned four fictional children’s ages, birth-order positions, bedroom locations, and team memberships before making age, birth-order, and team-membership judgments, respectively, with left–right responses. The birth-order task yielded a birth-order position × response side interaction consistent with an earlier-born–left/later-born–right mapping and a learned spatial location × response side interaction consistent with a same-side effect. In the age and team-membership tasks, neither focal interaction was reliable. A cross-experiment analysis supported task-related variation in the learned spatial location × response side interaction. These findings indicate that birth-order position and learned spatial location can each contribute to left–right spatial-response correspondence, whereas the age judgment did not yield a reliable younger-left/older-right pattern. More broadly, the findings support a task-sensitive, multi-source account of SNARC-like effects.