Face-to-face social interactions are such a common, everyday experience that the impressive array of processes underlying them may typically go unnoticed. Although seemingly effortless, the act of forming impressions of an individual or group can be viewed as an unfolding, multistage process that relies on the deployment of visual attention, activation of stored beliefs and feelings, integration of multiple sources of information, and the generation of explicit behaviors, among others. Several social psychological models of impression formation have been generated to explicate these processes, but some key assumptions have received less attention than others. This is due in part to methodological difficulties in studying processes that occur in quick temporal succession, as the component processes of impression formation likely do. In addition, many aspects of this process are thought to occur implicitly, requiring measures of processes about which perceivers have little conscious access. Finally, social norms and desirability concerns may obscure or alter some processes of interest.