Exploring the “Dark Matter” of Social Interaction: Systematic Review of a Decade of Research in Spontaneous Interpersonal Coordination

Abstract

Interpersonal coordination is a research topic that has attracted considerable attention this last decade both due to a theoretical shift from intra-individual to inter-individual processes and due to the development of new methods for recording and analyzing movements in ecological settings. Encompassing spatiotemporal behavioral matching, interpersonal coordination is considered as “social glue” due to its capacity to foster social bonding. However, the mechanisms underlying this effect are still unclear and recent findings suggest a complex picture. Goal-oriented joint action and spontaneous coordination are often conflated, making it difficult to disentangle the role of joint commitment from unconscious mutual attunement. Consequently, the goals of the present article are twofold: (1) to illustrate the rapid expansion of interpersonal coordination as a research topic and (2) to conduct a systematic review of spontaneous interpersonal coordination, summarizing its latest developments and current challenges this last decade. By applying Rapid Automatic Keyword Extraction and Latent Dirichlet Allocation algorithms, keywords were extracted from PubMed and Scopus databases revealing the large diversity of research topics associated with spontaneous interpersonal coordination. Using the same databases and the keywords “behavioral matching,” “interactional synchrony,” and “interpersonal coordination,” 1,213 articles were identified, extracted, and screened following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. A total of 19 articles were selected using the following inclusion criteria: (1) dynamic and spontaneous interactions between two unacquainted individuals (2) kinematic analyses, and (3) non-clinical and non-expert adult populations. The results of this systematic review stress the proliferation of various definitions and experimental paradigms that study perceptual and/or social influences on the emergence of spontaneous interpersonal coordination. As methods and indices used to quantify interpersonal coordination differ from one study to another, it becomes difficult to establish a coherent picture. This review highlights the need to reconsider interpersonal coordination not as the pinnacle of social interactions but as a complex dynamical process that requires cautious interpretation. An interdisciplinary approach is necessary for building bridges across scattered research fields through opening a dialogue between different theoretical frameworks and consequently provides a more ecological and holistic understanding of human social cognition.

Interpersonal synchronization of spontaneously generated body movements

“…The fact that spontaneous movements can synchronize interpersonally has two important implications. First, it indicates that the mechanisms underlying IMS are quite powerful, capable of triggering/inhibiting actions (in an observer) ex novo, not simply modulating the timing of ongoing actions (as previously observed, see 8 , 90 for a review). Indeed, even though our participants were not required to move, they did so in response to their partners’ movements.…”

Postural and gestural synchronization, sequential imitation, and mirroring predict perceived coupling of dancing dyads

“…According to our results, Similarity seems to relate to both gestural synchrony (specifically, to simultaneous slow horizontal sway) and to postural synchrony (specifically, to similar bounding volume dynamics), whereas Interaction is more associated with faster gestural Synchrony and with Imitation. As a methodological contribution, we have perceptually validated three novel approaches to model kinematic coupling, which is a complex dynamical process whose lack of standardized quantification methods (Ayache et al, 2021)-is shared with neighboring research realms (Cliff et al, 2022). Multivariate analysis techniques can help to clarify the perception of movement coupling and other issues both inside and outside the realm of music-induced movement.…”

Evaluating Interactional Synchrony in Full-Body Interaction with Autistic Children

“…Furthermore, it cannot be used in real-time because it cannot be built into systems to support live feedback. Computational tools include tools for generating time-series of multimodal movement data, such as video, wearable devices or motion tracking sensors [30,31]; and analysis tools measuring synchrony in and between groups of interacting agents [32]. But previous studies with autistic participants [28,33] that evaluated interactional synchrony focused on stationary experiments in controlled environments.…”