The myth of movement synchrony

Abstract

Earlier researchers have suggested that people synchronize their movements when interacting with one another. A rating method was compared to a micro-coding method of studying this movement synchrony. Videotapes of dyads in deceptive and truthful interactions had been rated for movement synchrony by naive observers in previous research. In the present study, these videotapes were micro-coded to identify movement onset times. Two movements were defined to be synchronous if they were initiated within.2 seconds of one another. Results indicated no correlation between the previous ratings of movement synchrony and synchrony identified by micro-coding. Synchrony judgments were positively correlated with the number of movements in an interaction that were reciprocated after a brief lag. The amount of time that interactants spent moving together was also positively correlated with synchrony judgments. A new statistical procedure was developed to determine the amount of synchrony that could be expected in an interaction by chance. Application of the procedure showed that in the truthful interactions analyzed here, participants performed fewer synchronous movement onsets than would be expected by chance. Other analyses indicated that in deceptive interactions the amount of time interactants spent moving together was less than expected by chance, and that interactants mimicked one another's movements. These results indicate that the movements in social interaction are more often sequentially contingent than simultaneous.