ABSTRACT Why are some groups successful while others fail? Why do some group members feel a strong connection to their group while others do not? Despite decades of research on human groups, there is a relative lack of knowledge regarding the interpersonal biobehavioral processes that emerge between group members as group interactions unfold, specifically regarding the coordinated synchronization patterns between group members from a neuroscience perspective. Interpersonal synchrony functions as “social glue” and allows us to connect, cooperate, and work together to achieve a joint goal. It is important to study groups from a biobehavioral perspective because grouping is evolutionary‐based and central to human living. Further, a key feature of groups is the emergence of interpersonal synchrony patterns that are supported by dedicated biological systems. Synchrony is critical to human life, yet it has not been fully described within a neurophysiological context in groups with more than two members until now. Thus, we are currently limited in our biobehavioral understanding of groups with more than two members. This paper will elaborate on the state‐of‐the‐art of neurophysiological synchrony research and how it may be applied to human group research. It will then articulate what is to be gained by extending the study of interpersonal synchrony to groups with more than two members and present an initial theoretical framework of group synchrony that will allow researchers to begin postulating hypotheses regarding synchrony specific to groups. A deeper understanding of interpersonal synchronization processes in human groups will allow us to reach a more mechanistic, process‐based understanding of groups and hopefully increase our ability to predict various groups' outcomes.