In this study, we investigate the conceptual structure of the metaphor “SIMILARITY IS PROXIMITY.” The results of four experiments suggest a tight mental link between similarity and proximity. Two experiments revealed that people judge entities to be more similar to each other when they are placed closely in space, while two other experiments showed that entities are judged to be closer to each other when they are thought to be more similar. We discuss this bidirectional metaphor transfer effect in light (...) of approaches to metaphor understanding, including the long-standing view that metaphorical mappings are assumed to be asymmetrical. We also consider the implications of this bi-directional mapping for high level cognition. (shrink)