Affect as Index is a tool that takes group physiological data as input, aggregates it across different demographic dimensions, and attaches them to media content. Users can review videotaped or prerecorded events by clicking on points of interest in a physiological graph. This software addresses two challenges: the difficulty of expressing and sharing emotions with others, and the laborious task of monitoring interpersonal interactions within natural settings. For the former, groups interested in discussing shared and dissimilar emotions evoked during experiences can use this tool to place context around their dialogue. For the latter, "meaningful moments" observed within natural interactions can be marked and superimposed on the physiological data collected. In this way, affect and observations of affect can be used to index group-level significant moments that occur within volumes of video data.