Being able to recognize and interpret other people’s behavior is key for adaptive social functioning. While research on biological motion processing has made great progress in understanding how this is done, it has largely neglected that we only rarely see people in isolation. To interpret situations with multiple people, we must first and foremost decide who is moving together and who is acting alone. In this project, I will test the hypothesis that we do this by binding individual observed movements into group movements based on visual cues that signal the presence of a social group. In WP1, I will develop a new paradigm that uses EEG frequency tagging (EEG-FT) to measure biological motion processing. In WP2, I will then use this paradigm to study how spatial and temporal relationships among observed movements influences movement processing. Next, in WP3, I will build on WP2 by making use of a unique feature of EEG-FT: its ability to obtain an objective signature of perceptual binding. Specifically, I will investigate if the binding of two movements depends on their spatial relationship and identity. Finally, in WP4, I will test whether adults with autism show altered binding of biological movements. This project has important implications: it extends theories of biological motion processing from the individual to the group level and may provide insight into why individuals with autism have difficulties with interpreting social interactions.