Coordinated social interaction belongs to our everyday life whenever individuals align their behavior with each other in time and space. A substantial part of social interaction and collective behavior consists in synchronized goal-directed actions involving two or more individuals. These actions are regulated by various factors that work together calibrated by appropriate coupling mechanisms within and between individuals and their brains. Hyperscanning studies (simultaneous signal recording from multiple individuals) has shown that synchronization within and between brains as well as within and between physiological systems and subsystems (e.g., respiratory, cardiac systems, body movements, etc.) plays a crucial role for social interaction phenomena. They can be described most effectively in terms of the cooperation of several parts of the system or subsystems. Emerging complex network dynamics and its topology represent an imprint of such complex systems’ behavior and have been outlined in several studies by means of a graph-theoretical approach. There has been an important growth in publications on inter-brain or hyper-brain connectivity and network dynamics over the last 20 years. However, a certain knowledge gap remains between behavioral and neural (and also other physiological and physical) representations or features and it requires further intensive research.