Citizens minimize information costs by obtaining political information and guidance from other individuals who have assumed the costs of acquiring and processing political information. A problem occurs because ideal informants, characterized by the joint presence of political expertise and shared viewpoints, are often unavailable or rare within the groups where individuals are located. Hence, individuals must often look beyond their own group boundaries to find such individuals, but obtaining information from individuals located beyond their own groups produces additional information costs. Moreover, the availability of ideal informants varies across groups and settings, with the potential to produce (1) biases in favor of some groups at the expense of others, (2) varying levels of polarization among groups, and (3) context dependent patterns of informant centrality. The paper’s analysis is based on a series of small group experiments, each of which involves two groups of seven subjects who communicate with one another via networked computers in order to obtain information on candidates. The aggregate implications of the experimental results are analyzed using an agent-based model.