Person Knowledge Is Independently Encoded by Allocentric and Egocentric Reference Frames Within Separate Brain Systems

Knowing the similarities among others is critical for navigating our social environments and building relationships. However, people can evaluate the similarity among others using two perspectives: other-to-other differences (allocentric similarity) or self-to-other differences (egocentric similarity). Here, we use functional magnetic resonance imaging (fMRI) to test whether the similarity of brain-response patterns when thinking of others and the self is predicted by behavioral models of allocentric and egocentric similarity in the representations of acquainted peers from 20 independent groups of adults (total <i>N</i> = 108; within-subjects design). Results show that both allocentric and egocentric similarity during person representation are reflected in brain-response similarity patterns when thinking of others, but they do so differentially and in nonoverlapping brain systems. These results suggest that the brain independently processes both allocentric and egocentric reference frames to encode trait information about conspecifics that we use to represent person knowledge about others within real-world social networks.