["Journal of Public Economic Theory, Volume 28, Issue 3, June 2026. ", "\nABSTRACT\nThis paper reports the results of an experiment on information spillovers between groups. We find that a player who is a member of multiple groups aggregates information and serves as a conduit through which information from one group spills over to another. We also find that such players are more influential than similarly situated players who are members of only a single group. We introduce a novel measure of the magnitude of information spillovers, and we identify the behavioral characteristics of the players that determine these magnitudes. While between‐group spillovers occur, we find that their magnitudes are smaller than social learning theory predicts.\n"]