Recent theoretical work has argued that in addition to the classical ventral (what) and dorsal (where/how) visual streams, there is a third visual stream on the lateral surface of the brain specialized for processing social information. Like visual representations in the ventral and dorsal streams, representations in the lateral stream are thought to be hierarchically organized. However, no prior studies have comprehensively investigated the organization of naturalistic, social visual content in the lateral stream. Here we used a data-rich approach to test the hypothesis that social action information is extracted hierarchically along this pathway. Social scenes pose several computational challenges beyond those of object recognition: they are often highly dynamic and involve relations between two or more people. To address these challenges, we curated a naturalistic stimulus set of 250 three-second videos of two people engaged in everyday actions. Each clip was richly annotated for its low-level visual features, mid-level scene & object properties, visual social primitives (including the distance between people and the extent to which they were facing), and high-level information about social interactions and affective content. Using a condition-rich fMRI experiment and a within-subject encoding model approach, we found that low-level visual features are represented in early visual cortex (EVC) and middle temporal area (MT), mid-level visual-social features in extrastriate body area (EBA) and lateral occipital complex (LOC), and high-level social interaction information along the superior temporal sulcus (STS). Communicative interactions, in particular, explained unique variance in anterior regions of the STS, even when accounting for variance explained by all other labeled features. Taken together, these results provide support for representation of increasingly abstract social visual content—consistent with hierarchical organization—along the lateral visual stream and suggest that recognizing communicative actions may be a key computational goal of the STS and lateral pathway.