Research on interpersonal coordination can be traced back to the early 1960s, when video recording began to be used 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 on 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, describing their major findings, levels of description and limitations. We group them into three categories: video analysis, motion tracking, and psychophysiological and neurophysiological techniques. The revised evidence suggests that interpersonal coordination encompasses a family of morphological and temporal synchronies at different levels and that it is tightly 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.

Body synchronization between interacting people involves coordinative movements in time, 5 space and form. The introduction of newer technologies for automated video analysis and motion 6 tracking has considerably improved the accurate measurement of coordination, particularly in 7 temporal and spatial terms. However, the form of interpersonal coordination has been less 8 explored. In the present study we address this gap exploring the effect of trust on temporal and 9 morphological patterns of interpersonal coordination. We adapted an optical motion-capture 10 system to record spontaneous body movements in pairs of individuals engaged in natural 11 conversations. We conducted two experiments in which we manipulated trust through a breach 12 of expectancy (Study 1: 10 trustful and 10 distrustful participants) and friendship (Study 2: 20 13 dyads of friends and 20 dyads of strangers). In Study 1, results show the participants’ strong, 14 early mirror-like coordination in response to the confederates’ breach of trust. In Study 2, imitative 15 coordination tended to be more pronounced in pairs of friends than in pairs of non-friends. Overall, 16 our results show not only that listeners move in reaction to speakers, but also that speakers react 17 to listeners with a chain of dynamic coordination patterns affected by the immediate disposition 18 of, and long-term relationship with, their interlocutors.

The temporal dynamics of parent-infant synchrony have been well documented. In recent years, the introduction of more accurate technologies for tracking movements has allowed the distinction of different morphological patterns of dyadic coordination. However, the potential of these technologies to explore infant-adult synchrony has not yet been explored. In the present study, we examined the temporal, spatial, and morphological synchrony patterns of infant-unknown adult pairs participating in a storytime session by a motion capture system (mocap). We find low but significant correlation levels of body synchrony between infants and unknown adults. This synchronized coactivity adopted two differentiated forms: mirror-like and anatomical. While the infants’ movements mirrored those of the adults with a lag (0.9 s), the adults’ reactions to the infants were anatomical with delay (0.4 s). This evidence could contribute novel insights to rethink synchrony and its measurement.

Infant-adult synchrony has been reported through observational and experimental studies. Nevertheless, synchrony is addressed differently in both cases. While observational studies measure synchrony in spontaneous infant-adult interactions, experimental studies manipulate it, inducing nonspontaneous synchronous and asynchronous interactions. A still unsolved question is to what extent differ spontaneous synchrony from the nonspontaneous one, experimentally elicited. To address this question, we conducted a study to compare synchrony in both interactional contexts. Forty-three 14-month-old infants were randomly assigned to one of two independent groups: (1) the spontaneous interaction context, consisting of a storytime session; and (2) the nonspontaneous interaction context, where an assistant bounced the infant in synchrony with a stranger. We employed an optical motion capture system to accurately track the time and form of synchrony in both contexts. Our findings indicate that synchrony arising in spontaneous exchanges has different traits than synchrony produced in a nonspontaneous interplay. The evidence presented here offers new insights for rethinking the study of infant-adult synchrony and its consequences on child development.

The temporal dimension of interpersonal macro- and micro-coordinations between young children and social partners, as well as its functions, has been well documented. However, the different morphologies that bodily micro-coordination can adopt during these interactions have received considerably less attention. This research studied the temporality and morphology of spontaneous child-adult micro-coordinations and their associated functions. For this purpose, three-year-old children (N = 35) were randomly assigned to storytelling sessions based on emotional or referential stories. Using motion capture technology, we traced rapid and spontaneous coordinations between torso movements, ranging from 0 to 1000 milliseconds. Results show that both mirror-like and anatomical coordinations spontaneously emerge in interactions between 3-year-old children and unfamiliar adults. Importantly, slightly delayed in time, mirror-like coordinations predominantly occur in emotional interactions, while zero-lag, anatomical coordinations occur in referential interactions. These results suggest that these morphologies might indeed inform different functions of coordination, as previously theorized in the literature. The evidence found could contribute to a better understanding of how interpersonal coordination shapes social interaction very early in development.