Data_Sheet_1.PDF

Body synchronization between interacting people involves coordinative movements in time, space and form. The introduction of newer technologies for automated video analysis and motion tracking has considerably improved the accurate measurement of coordination, particularly in temporal and spatial terms. However, the form of interpersonal coordination has been less explored. In the present study we address this gap by exploring the effect of trust on temporal and morphological patterns of interpersonal coordination. We adapted an optical motion-capture system to record spontaneous body movements in pairs of individuals engaged in natural conversations. We conducted two experiments in which we manipulated trust through a breach of expectancy (Study 1: 10 trustful and 10 distrustful participants) and friendship (Study 2: 20 dyads of friends and 20 dyads of strangers). In Study 1, results show the participants' strong, early mirror-like coordination in response to the confederates' breach of trust. In Study 2, imitative coordination tended to be more pronounced in pairs of friends than in pairs of non-friends. Overall, our results show not only that listeners move in reaction to speakers, but also that speakers react to listeners with a chain of dynamic coordination patterns affected by the immediate disposition of, and long-term relationship with, their interlocutors.

Frontiers in psychology, 2018

Body synchronization between interacting people involves coordinative movements in time, space and form. The introduction of newer technologies for automated video analysis and motion tracking has considerably improved the accurate measurement of coordination, particularly in temporal and spatial terms. However, the form of interpersonal coordination has been less explored. In the present study we address this gap by exploring the effect of trust on temporal and morphological patterns of interpersonal coordination. We adapted an optical motion-capture system to record spontaneous body movements in pairs of individuals engaged in natural conversations. We conducted two experiments in which we manipulated trust through a breach of expectancy (Study 1: 10 trustful and 10 distrustful participants) and friendship (Study 2: 20 dyads of friends and 20 dyads of strangers). In Study 1, results show the participants' strong, early mirror-like coordination in response to the confederates&#...

Inputs-Outputs '13: Proceedings of the 2013 inputs-outputs conference: An interdisciplinary conference on engagement in HCI and performance, 2013

Social interaction is a core aspect of human life that affects individuals' physical and mental health. Social interaction usually leads to mutual engagement in diverse areas of cognitive, emotional, physiological and physical activity involving both interacting persons and subsequently impacting the outcome of these interactions. A common approach to the analysis of social interaction is the study of the verbal content transmitted between sender and receiver. However, additional important processes and dynamics are occurring in other domains too, for example in the area of nonverbal behaviour. In a series of studies, we have looked at interactional synchrony -- the coordination of two persons' movement patterns -- and its association with relationship quality and with the outcome of interactions. Using a computer-based algorithm, which automatically quantifies a person's body-movement, we were able to objectively calculate interactional synchrony in a large number of dyads interacting in various settings. In a first step, we showed that the phenomenon of interactional synchrony existed at a level that was significantly higher than expected by chance. In a second step, we ascertained that across different settings -- including patient-therapist dyads and healthy subject dyads -- more synchronized movement was associated with better relationship quality and better interactional outcomes. The quality of a relationship is thus embodied by the synchronized movement patterns emerging between partners. Our studies suggested that embodied cognition is a valuable approach to research in social interaction, providing important clues for an improved understanding of interaction dynamics.

Journal of Experimental Psychology: Human Perception and Performance, 2003

The research was designed to evaluate interpersonal coordination during conversation with a new measurement tool. The experiment uses an analysis based on recurrence strategies, known as cross recurrence quantification, to evaluate the shared activity between 2 postural time series in reconstructed phase space. Pairs of participants were found to share more locations in phase space (greater recurrence) in conditions where they were conversing with one another to solve a puzzle task than in conditions in which they conversed with others. The trajectories of pairs of participants also showed less divergence when they conversed with each other than when they conversed with others as well. This is offered as objective evidence of interpersonal coordination of postural sway in the context of a cooperative verbal task. Language use is really a form of joint action. A joint action is one that is carried out by an ensemble of people acting in coordination with each other. (Clark, 1996, p. 3) Clark (1996) has suggested that language use occurs prototypically in the context of cooperative activities that he calls "joint actions." These are activities in which two or more people engage to achieve mutual goals. The speech that occurs moves the activities forward toward goal achievement. By definition, cooperative activities require interpersonal coordination. Many investigators have observed apparent indices of coordination in the context of cooperative activities that involve speech. All of the indices are examples of interpersonal imitation or entrainment. For example, individuals speaking cooperatively are found to converge in their dialect (see Giles, Coupland, & Coupland, 1991, for a review). Speakers have also been found to converge in speaking rate (Street, 1984), vocal intensity (Natale, 1975), and pausing frequency (Cappella & Planalp, 1981; see Cappella, 1981, for a review). In addition, listeners to a speaker whom they find engaging tend to mirror the postures of the speaker (LaFrance, 1982). Listeners are also reported to move in time with the rhythms of a speaker's speech (exhibiting "interactional synchrony"; Condon & Ogston, 1971; Newtson, 1994). Findings, particularly of movement entrainment among conversational partners, are intriguing, because they appear to index the interpersonal coordination that must occur if the joint activities are to be completed. However, most findings of movement entrainment are based on fairly subjective, observational procedures. For example, Condon and Ogston (1971) assessed interactional synchrony by hand scoring videotapes of listener movements and hand marking the accompanying speech for its rhythmic properties. Although this work was painstaking and, apparently, quite carefully done, it is open to error. Speech rhythms in particular are quite difficult to document. Newtson and colleagues (see Newtson, Engquist, & Bois, 1977; Newtson, Hairfield, Bloomingdale, & Cutino, 1987) have also offered strategies for evaluating the coordination dynamics of participants engaged in various activities, including conversation. These strategies involve visual analysis of behavior sequences of recorded interactions. Stick-figure tracings are made of each actor in a sequence at specific intervals. Each successive tracing is compared for changes in joint angles. For 17 possible joint-angle changes, a value of 0 or 1 is assigned, yielding a score between 0 and 17 for each frame. This strategy yields remarkably high reliabilities and appears quite robust. The coded sequences (time series) can then be translated into spectral profiles, reflecting the periodicity of the movement sequence and also, apparently, the class of movements (e.g., throwing vs. catching a ball). Finally, the spectral profiles of two time series may be

Social chemistry is a critical aspect of our life as human beings. We use our body to share information with others and to understand them. Recently, studies suggest that movement synchronization during social interaction might be important for social bonding. The current study aimed to understand how different features of movement influence both predictability and complexity of the interaction within dyads, assuming that both are inherent for successful social interaction. The experiment took place in four different round-robin sessions. The participants (98 pairs, comprised out of 33 individuals) played the "Mirror Game", in which they had to move their hands as coordinately as they could, without using verbal communication. After each game, the participants filled a questionnaire about their subjective experience and their impression of their partner. All sessions were filmed and preprocessed using motion energy analysis to extract a time-series representing participants' velocity throughout time. Using cross recurrence quantification analysis and cross-correlation, we found that the interplay between pausing and accelerating, as well as the amount of movements, determined the predictability (dyad movement synchronization) and complexity (entropy) of the interactions. More so, increased predictability and complexity were correlated with increased social bonding and mutual understanding. Thus, our findings suggest that the interplay between predictability and complexity of movement is important for successful non-verbal social interaction.

Language & Communication, 2017

In everyday circumstances, humans use a variety of cues to draw rich inferences about the nature of interaction. Among these, we focus on sequences of self-regulatory movements, such as touching behaviours and postural changes, that have long been related to interpersonal coordination understood both in terms of mimicry and synchrony. So far, there has been a severe lack of studies on the third party perception of interactional phenomena, including self-regulators. Here, we investigate which elements of the interactional dynamics induce the perception of interactants' behaviours (represented by self-regulators) as casually related, and show that the most important factor responsible for such attribution is the similarity of observed movements On a more general plane, we hope to make a step towards uncovering perceptual biases that evolved for interpersonal coordination, thus shedding some light on the human interactional potential and its evolution. Highlights • Self-regulatory movements and their perception are of direct interest to the theory of the cooperative signalling characteristic of language. • Movement similarity and temporal proximity are the most perceptually salient characteristics of self-regulators. • The perceptual biases towards mimicry and synchrony could have evolved for interpersonal coordination.

Abstract The study of interpersonal synchrony examines how interacting individuals grow to have similar behavior, cognition, and emotion in time. Many of the established methods of analyzing interpersonal synchrony are costly and time-consuming; the study of bodily synchrony has been especially laborious, traditionally requiring researchers to hand-code movement frame by frame. Because of this, researchers have been searching for more efficient alternatives for decades.

Research regarding interpersonal coordination can be traced back to the early 1960s when video recording began to be utilized in communication studies. Since then, technological advances have extended the range of techniques that can be used to accurately study interactional phenomena. Although such a diversity of methods contributes to the improvement of knowledge concerning interpersonal coordination, it has become increasingly difficult to maintain a comprehensive view of the field. In the present article, we review the main capture methods by describing their major findings, levels of description and limitations. We group them into three categories: video analysis, motion tracking, and psychophysiological and neurophysiological techniques. Revised evidence suggests that interpersonal coordination encompasses a family of morphological and temporal synchronies at different levels and that it is closely related to the construction and maintenance of a common social and affective space. We conclude by arguing that future research should address methodological challenges to advance the understanding of coordination phenomena.

Coordinated behavior patterns are one of the pillars of social interaction. Researchers have recently shown that movement synchrony influences ratings of rapport, and the extent to which groups are judged to be a unit. The current experiments investigated the hypothesis that observers infer a shared psychological state from synchronized movement rhythms, influencing attributions of rapport and entitativity judgments. Movement rhythms of observed individuals are manipulated between participants (Experiment 1) or kept constant while source of the emerging movement synchrony is manipulated (Experiment 2), and both rapport and perceived entitativity are measured with multiple item questionnaires. The findings support the assumption that movement synchrony increases attributed rapport and perceived entitativity. Furthermore, meditational analyses reveal that the effects of movement synchrony on perceived unity are not purely perceptual in nature, but caused by psychological inferences. Observers infer the degree to which individuals are a social unit from their movement rhythms.

Conversation between two people involves subtle non-verbal coordination but the parameters and timing of this coordination remain unclear, which limits our models of social coordination mechanisms. We implemented high-resolution motion capture of human head motion during structured conversations. Using pre-registered analyses, we quantify cross-participant wavelet coherence of head motion as a measure of non-verbal coordination, and report two novel results. First, head pitch (nodding) at 2.6 – 6.5 Hz shows below-chance coherence between people. This is driven by fast-nodding behaviour from the person listening, and is a newly defined nonverbal behaviour which may act as an important social signal. Second, head pitch movements at 0.2-1.1 Hz show above-chance coherence with a constant lag of around 600msec between a leader and follower. This is consistent with reactive (rather than predictive) models of mimicry behaviour. These results provide a step towards the quantification of rea...