As a social species, humans live in complexly bounded social groups. In order to navigate these networks, humans rely on a set of social-cognitive processes, including social working memory. Here, we designed a novel network memory task to study working memory for social versus non-social network information across 241 participants (18-65 years) in a tightly controlled, preregistered study. We show that humans demonstrate a working memory advantage for social, relative to non-social, network information. We also observed a self-relevant positivity bias, but an 'other' negativity bias. These findings are interpreted in the context of an evolutionary need to belong to one's social group, to identify risks to one's social safety and to appropriately track one's social status within a complex network of social relationships.