The cognitive demands of navigating large groups comprised of many varied, intense, and enduring social bonds are thought to have significantly shaped human brain evolution. Yet, much remains to be understood about how individuals track, encode, and are influenced by the structure of the social networks that they inhabit. This talk will provide an overview of recent work integrating theory and methods from social psychology, cognitive neuroscience, and social network analysis, as well as the motivation for combining these lines of inquiry. One set of studies tests if, when, and how people retrieve knowledge of familiar others’ positions in their real-world social networks when encountering them. Related research tests how this knowledge, once retrieved, shapes downstream processing and behavior. An additional set of studies tests if human social networks exhibit assortativity in how their members perceive, interpret, and respond to their environment. Consistent with this possibility, inter-individual similarities of neural responses to naturalistic stimuli accurately predict the distance between individuals in their shared social network, such that friends have exceptionally similar responses to the world around them. All human cognition is embedded within social networks, but research on information processing within individuals has progressed largely separately from research on the social networks in which individuals are embedded. The set of findings to be reviewed in this talk suggests that integrating approaches from social psychology, neuroscience, and social network analysis can provide new insights into how individuals perceive, shape, and are shaped by the structure of their social world.