What are the psychological drivers that lead to successful information propagation between communicators and receivers of shared messages? What factors lead communicators to share information with others, and receivers to be successfully influenced by the information? The current dissertation focuses on the role of mentalizing, or considering other people’s mental states, as one factor that leads to successful information propagation between communicators and receivers. Study 1 of this dissertation focused on the role of mentalizing in communicators of influence and provided behavioral evidence suggesting that mentalizing causally increases communicators’ likelihood to share information. Specifically, instructing information sharers to consider how sharing would affect potential receivers’ tendencies to feel positively, emotional, and focus inward led communicators to feel closer to potential receivers of their messages, leading to increased likelihood of sharing. Study 2 of this dissertation used neuroimaging to test the role of mentalizing in receivers of influence and showed that brain activity in the mentalizing regions of receivers is associated with increased likelihood of successful social influence in a paradigm that parallels the current online environment. Receivers were significantly more likely to change their own recommendations about mobile game apps when considering peer recommendations that elicited more mentalizing activity, and this effect was driven by negatively framed peer recommendations. Further, Study 2 provided novel evidence suggesting that in this context, the brain’s mentalizing system may work independently from the value system in leading to successful social influence. Finally, Study 3 of this dissertation tested whether individual differences in communicators’ tendencies to mentalize and consider social factors in decisions to share information are associated with higher rate of success in achieving social influence. Study 3 did not find support for this account, potentially due to the explicit social nature of the experimental paradigm that led to decreased variability in individual differences in mentalizing. Together, the current dissertation advances theories of information propagation and social influence by highlighting the role of mentalizing in both communicators and receivers of influence while also providing important insight on possible boundary conditions when individual differences in mentalizing may not be associated with more successful communication.