Measuring the Dynamics of Interactional Synchrony

Past research has revealed that natural social interactions contain interactional synchrony. The present study describes new methods for measuring interactional synchrony in natural interactions and evaluates whether the behavioral synchronization involved in social interactions is similar to dynamical synchronization found generically in nature. Two methodologies, a rater-coding method and a computational video image method, were used to provide time series representations of the movements of the co-actors as they enacted a series of jokes (i.e., knock-knock jokes). Cross-spectral and relative phase analyses of these time series revealed that speakers' and listeners' movements contained rhythms that were not only correlated in time but also exhibited phase synchronization. These results suggest that computational advances in video and time series analysis have greatly enhanced our ability to measure interactional synchrony in natural interactions. Moreover, the dynamical synchronization in these natural interactions is commensurate with that found in more stereotyped tasks, suggesting that similar organizational processes constrain bodily activity in natural social interactions and, hence, have implications for the understanding of joint action generally.