Rank labels scaffold social cognitive maps in the hippocampal-entorhinal system

How do humans construct mental representations of social hierarchies in the absence of direct interpersonal interactions? In many real-world contexts, humans rely on symbolic rank labels-such as titles or performance ratings-to navigate social hierarchies, yet how these abstract labels shape neural representations of social structure remains unclear. Using fMRI, we investigated whether learning face-rank associations along two orthogonal social dimensions-competence and morality-engages spatial coding mechanisms within the hippocampal-entorhinal system. Twenty-four participants completed an extensive three-day protocol-including baseline trait evaluation (Day 1), extensive behavioral training (Day 2), and multidimensional decision-making and spatial reconstruction tasks (Day 3). Behavioral results support that larger rank distances produced faster and more accurate hiring decisions, indicating reliance on an internal spatial map. Subsequent representational-similarity analysis further revealed that the hippocampus encoded Euclidean distances between individuals, whereas the entorhinal cortex expressed a hexadirectional grid-like pattern that aligned with the inferred directions of social relationships. These converging behavioral and neural results demonstrate that explicit symbolic ranks rapidly scaffold a two-dimensional cognitive map of social hierarchy, repurposing spatial-navigation mechanisms for abstract social reasoning. This insight advances social-cognitive neuroscience and highlights principles that could inform artificial-intelligence systems designed for hierarchical reasoning and decision-making in complex social environments.